diff --git a/.github/skills/ai-context/SKILL.md b/.github/skills/ai-context/SKILL.md
new file mode 100644
index 0000000000..c51a968344
--- /dev/null
+++ b/.github/skills/ai-context/SKILL.md
@@ -0,0 +1,111 @@
+---
+name: ai-context
+description: Use when creating, updating, or maintaining AI documentation files (AGENTS.md, CLAUDE.md, skills). Covers file structure, conventions, and guidelines for evolving AI context.
+---
+
+# AI Context Documentation
+
+How to write and maintain the structured documentation that AI coding assistants consume.
+
+## File Hierarchy
+
+```
+AGENTS.md                            # Root context — always loaded by agents
+CLAUDE.md                            # Required for Claude Code (loads AGENTS.md)
+.github/skills/<topic>/SKILL.md      # On-demand detailed context
+packages/<name>/AGENTS.md            # Package-specific context
+<any-folder>/AGENTS.md               # Folder-specific context
+```
+
+## Root Files
+
+### AGENTS.md
+
+Always loaded on every interaction. Keep it **minimal** to save tokens.
+
+Must contain:
+- One-line project description
+- Essential commands (run, test, build)
+- Repository structure overview (top-level dirs only)
+- Skills index table linking to each `SKILL.md`
+- Key entry points for common tasks
+
+Must **not** contain:
+- Detailed explanations (put those in skills)
+- Code examples longer than one line
+- Duplicated content from skills
+
+### CLAUDE.md
+
+Required because Claude Code doesn't load `AGENTS.md` natively. It bridges Claude Code into the same context system. Contents:
+
+```markdown
+Read [AGENTS.md](AGENTS.md) before starting any task.
+
+## Skills
+
+Load these for detailed context on specific topics:
+
+| Skill | When to use |
+|-------|-------------|
+| [<name>](.github/skills/<name>/SKILL.md) | <description> |
+```
+
+Keep in sync with the skills table in `AGENTS.md`.
+
+## Skills
+
+### Creating a Skill
+
+1. Create `.github/skills/<topic>/SKILL.md`
+2. Add YAML frontmatter with `name` and `description`
+3. Add an entry to the skills table in both `AGENTS.md` and `CLAUDE.md`
+
+### SKILL.md Format
+
+```markdown
+---
+name: <topic>
+description: <when an agent should load this — be specific about triggers>
+---
+
+# <Title>
+
+<One-line summary.>
+
+## <Sections organized by task>
+```
+
+### Writing Guidelines
+
+- **Frontmatter `description`**: Write it as a trigger — what task or question should cause an agent to load this skill
+- **Be concise**: Use tables over prose, code snippets over explanations
+- **Be specific**: File paths, command names, function signatures — not vague descriptions
+- **No duplication**: If info exists in another skill, reference it instead of repeating
+- **Actionable structure**: Organize by what the agent needs to *do*, not by architecture
+
+## Package & Folder Context
+
+Add `AGENTS.md` inside a package or folder when:
+- The directory has non-obvious conventions agents keep getting wrong
+- There are local commands, patterns, or gotchas not covered by root docs
+
+Keep these files very short — a few lines of context is often enough.
+
+## When to Update
+
+| Trigger | Action |
+|---------|--------|
+| Agent repeatedly asks about a topic | Create a new skill |
+| Agent gets something wrong despite docs | Refine the relevant skill |
+| New package/directory with unique patterns | Add a local `AGENTS.md` |
+| Architecture or tooling changes | Update affected skills |
+| Skill grows too large | Split into multiple skills |
+| Skills table changes | Update both `AGENTS.md` and `CLAUDE.md` |
+
+## Principles
+
+1. **Token budget**: Root files stay small; details go in skills
+2. **Load on demand**: Skills are only read when relevant to the task
+3. **Living docs**: Update when patterns change — stale docs are worse than none
+4. **Cross-platform**: `AGENTS.md` + `.github/skills/` is the shared convention; `CLAUDE.md` bridges Claude Code which doesn't load `AGENTS.md` natively
diff --git a/.github/skills/codebase/SKILL.md b/.github/skills/codebase/SKILL.md
new file mode 100644
index 0000000000..32ba7872fe
--- /dev/null
+++ b/.github/skills/codebase/SKILL.md
@@ -0,0 +1,110 @@
+---
+name: codebase
+description: Use when understanding the build system, modifying CLI commands, working with isobuild, or navigating the tools/ directory. Covers build pipeline flow and file locations.
+---
+
+# Codebase
+
+Meteor's build system (Isobuild) and CLI structure.
+
+## Overview
+
+Meteor is a full-stack JavaScript platform with:
+- **Core packages** in `/packages`
+- **Build system (Isobuild)** in `/tools/isobuild`
+- **CLI tool** in `/tools/cli`
+- **Real-time data layer** via DDP
+- **Mobile support** via Cordova
+
+## Build Pipeline
+
+1. **CLI** (`tools/cli/main.js`) → parses commands
+2. **Project Context** (`project-context.js`) → resolves packages, dependencies
+3. **Isobuild** (`tools/isobuild/`)
+   - Bundler (`bundler.js`) → orchestrates build
+   - Compiler (`compiler.js`) → compiles packages
+   - Linker (`linker.js`) → wraps modules
+   - Build plugins (Babel, TypeScript, CSS)
+4. **Output** → `star.json`, programs
+5. **Runners** (`tools/runners/`) → run-app.js, run-mongo.js, run-hmr.js
+6. **Live App** → DDP Server ↔ Minimongo ↔ UI
+
+## Directory Structure
+
+```
+tools/
+├── cli/                   # Command-line interface
+├── isobuild/              # Build system core
+├── packaging/             # Package management
+├── runners/               # App execution engines
+├── fs/                    # File system utilities
+├── cordova/               # Mobile/Cordova support
+├── static-assets/         # Project templates
+└── project-context.js     # Dependency resolution
+```
+
+## CLI (`tools/cli/`)
+
+| File | Description |
+|------|-------------|
+| `main.js` | Entry point, command dispatcher |
+| `commands.js` | Main command implementations |
+| `commands-packages.js` | Package management commands |
+| `commands-cordova.js` | Cordova/mobile commands |
+
+**Commands:** `meteor create`, `run`, `build`, `deploy`, `add/remove`, `mongo`, `shell`
+
+## Isobuild (`tools/isobuild/`)
+
+| File | Description |
+|------|-------------|
+| `bundler.js` | High-level bundling orchestration |
+| `compiler.js` | Package compilation |
+| `linker.js` | Module wrapping and linking |
+| `import-scanner.ts` | Import statement parsing |
+| `compiler-plugin.js` | Compiler plugin API |
+| `isopack.js` | Package format handling |
+
+## Runners (`tools/runners/`)
+
+| File | Description |
+|------|-------------|
+| `run-app.js` | Web application runner |
+| `run-mongo.js` | MongoDB server runner |
+| `run-hmr.js` | Hot module reload runner |
+| `run-all.js` | Multi-runner orchestration |
+
+## Build Targets
+
+| Target | Description |
+|--------|-------------|
+| `web.browser` | Modern browsers |
+| `web.browser.legacy` | Legacy browsers (IE11) |
+| `web.cordova` | Cordova mobile apps |
+| `server` | Node.js server |
+
+## Package Relationships
+
+- `tools-core` → rspack, future integrations
+- `accounts-base` → all accounts-* packages
+- `ddp-server` + `ddp-client` → realtime communication
+- `mongo` → minimongo (client-side)
+- `webapp` → all HTTP handling
+
+## Project Templates
+
+Via `meteor create --<template>`: `react`, `vue`, `svelte`, `angular`, `blaze`, `typescript`, `tailwind`, `solid`, `apollo`, `minimal`, `bare`, `full`
+
+## Environment Variables
+
+| Variable | Purpose |
+|----------|---------|
+| `METEOR_PROFILE` | Build profiling |
+| `METEOR_PACKAGE_DIRS` | Additional package paths |
+| `METEOR_DEBUG_BUILD` | Verbose build output |
+
+## Troubleshooting
+
+- **Package not found:** Check `package.js` name, run `meteor reset`
+- **Build plugin not running:** Check `archMatching`, file extensions
+- **npm issues:** Clear `.meteor/local/`, run `meteor npm install`
diff --git a/.github/skills/conventions/SKILL.md b/.github/skills/conventions/SKILL.md
new file mode 100644
index 0000000000..1767100ca5
--- /dev/null
+++ b/.github/skills/conventions/SKILL.md
@@ -0,0 +1,188 @@
+---
+name: conventions
+description: Use when writing new packages, adding CLI commands, creating build plugins, or following Meteor code patterns. Covers package.js structure, file naming, and common code patterns.
+---
+
+# Code Conventions
+
+Package structure, file naming, and code patterns for the Meteor codebase.
+
+## Package Structure
+
+Every Meteor package follows this structure:
+
+```
+packages/my-package/
+├── package.js          # Package manifest (name, version, dependencies, exports)
+├── my-package.js       # Main implementation (or split by concern)
+├── my-package-server.js # Server-only code (optional)
+├── my-package-client.js # Client-only code (optional)
+├── my-package-tests.js  # Tests (loaded via api.addFiles in test mode)
+└── README.md           # Documentation (optional)
+```
+
+## Package.js Anatomy
+
+```javascript
+Package.describe({
+  name: 'my-package',
+  version: '1.0.0',
+  summary: 'Brief description',
+  git: 'https://github.com/meteor/meteor.git',
+  documentation: 'README.md'
+});
+
+Package.onUse(function(api) {
+  api.versionsFrom(['3.0']);  // Minimum Meteor version
+
+  api.use([
+    'ecmascript',            // ES2015+ support
+    'mongo',                 // MongoDB integration
+    'tracker'                // Reactivity (client)
+  ]);
+
+  api.use('accounts-base', { weak: true }); // Optional dependency
+
+  api.mainModule('my-package-server.js', 'server');
+  api.mainModule('my-package-client.js', 'client');
+
+  api.export('MyPackage');   // Global export
+});
+
+Package.onTest(function(api) {
+  api.use(['tinytest', 'my-package']);
+  api.addFiles('my-package-tests.js');
+});
+
+Npm.depends({
+  'lodash': '4.17.21'        // npm dependencies
+});
+```
+
+## File Naming Conventions
+
+| Pattern | Purpose |
+|---------|---------|
+| `*-server.js` | Server-only code |
+| `*-client.js` | Client-only code |
+| `*-common.js` | Shared code |
+| `*-tests.js` | Test files |
+| `*.d.ts` | TypeScript declarations |
+
+## Common Patterns
+
+### Adding a New Core Package
+
+1. Create directory in `/packages/my-package/`
+2. Add `package.js` with proper dependencies
+3. Implement functionality with proper exports
+4. Add tests in `*-tests.js`
+5. Update version numbers if needed
+
+### Modifying Build System
+
+Key files to understand:
+- `/tools/isobuild/bundler.js` - High-level bundling
+- `/tools/isobuild/compiler.js` - Package compilation
+- `/tools/project-context.js` - Dependency resolution
+- `/tools/cli/commands.js` - CLI command handlers
+
+### Adding CLI Commands
+
+Edit `/tools/cli/commands.js` or create new command file:
+
+```javascript
+main.registerCommand({
+  name: 'my-command',
+  options: {
+    'option-name': { type: String, short: 'o' }
+  },
+  catalogRefresh: new catalog.Refresh.Never()
+}, function(options) {
+  // Implementation
+});
+```
+
+### WebApp Middleware Pattern
+
+```javascript
+import { WebApp } from 'meteor/webapp';
+
+// Add middleware before Meteor's default handlers
+WebApp.rawConnectHandlers.use('/api', (req, res, next) => {
+  // Runs before authentication
+  next();
+});
+
+// Add middleware after authentication
+WebApp.connectHandlers.use('/api', (req, res, next) => {
+  // req.userId available if authenticated
+  next();
+});
+```
+
+### Build Plugin Pattern
+
+```javascript
+// In package.js
+Package.registerBuildPlugin({
+  name: 'compile-my-files',
+  use: ['ecmascript', 'caching-compiler'],
+  sources: ['plugin.js'],
+  npmDependencies: { 'my-compiler': '1.0.0' }
+});
+
+// In plugin.js
+Plugin.registerCompiler({
+  extensions: ['myext'],
+  archMatching: 'web'
+}, () => new MyCompiler());
+
+class MyCompiler extends CachingCompiler {
+  getCacheKey(inputFile) {
+    return inputFile.getSourceHash();
+  }
+
+  compileOneFile(inputFile) {
+    const source = inputFile.getContentsAsString();
+    const compiled = transform(source);
+    inputFile.addJavaScript({
+      data: compiled,
+      path: inputFile.getPathInPackage() + '.js'
+    });
+  }
+}
+```
+
+### Using tools-core in Packages
+
+```javascript
+// In package.js
+api.use('tools-core');
+
+// In implementation
+import {
+  logProgress,
+  checkNpmDependencyExists,
+  getMeteorAppConfig,
+  spawnProcess
+} from 'meteor/tools-core';
+
+// Check and install dependencies
+if (!checkNpmDependencyExists('@rspack/core')) {
+  installNpmDependency(['@rspack/core@^1.7.1']);
+}
+
+// Spawn external process
+const proc = spawnProcess('npx', ['rspack', 'build'], {
+  cwd: getMeteorAppDir(),
+  onStdout: (data) => logProgress(data)
+});
+```
+
+## Version Patterns
+
+Meteor uses `X.Y.Z-rcN.M` versioning where:
+- `X.Y.Z` - Semantic version
+- `rcN` - Release candidate number
+- `M` - Package-specific revision
diff --git a/.github/skills/modern-tools/SKILL.md b/.github/skills/modern-tools/SKILL.md
new file mode 100644
index 0000000000..cfcacdb09a
--- /dev/null
+++ b/.github/skills/modern-tools/SKILL.md
@@ -0,0 +1,246 @@
+---
+name: modern-tools
+description: Use when working with tools-core utilities, rspack integration, or modern tooling. Covers logging, npm management, process spawning, git helpers, and Meteor app configuration APIs.
+---
+
+# Modern Tools
+
+Utility packages for modern tooling, bundler integrations, and native solutions.
+
+## tools-core (`/packages/tools-core`)
+
+Central utility package providing helpers for npm, logging, process management, and Meteor configuration. This is the foundation for modern tool integrations.
+
+### Logging Module (`lib/log.js`)
+
+```javascript
+import { logProgress, logError, logInfo, logSuccess } from 'meteor/tools-core';
+
+logProgress('Building application...');  // Blue
+logSuccess('Build complete');            // Green
+logError('Build failed');                // Red
+logInfo('Using Rspack bundler');         // Purple
+```
+
+Respects `METEOR_DISABLE_COLORS` environment variable.
+
+### NPM Management Module (`lib/npm.js`)
+
+| Function | Description |
+|----------|-------------|
+| `getNodeBinaryPath(binaryName)` | Gets path to Node binaries (npm, npx, node) |
+| `checkNpmDependencyExists(dep, opts)` | Checks if npm package is installed |
+| `checkNpmBinaryExists(binary, opts)` | Checks if binary exists in node_modules/.bin |
+| `checkNpmDependencyVersion(dep, opts)` | Validates semver with conditions (gte, lt, eq) |
+| `installNpmDependency(deps, opts)` | Installs dependencies (npm/yarn, dev/exact flags) |
+| `getNpmCommand(args)` | Returns npm command with `meteor npm` fallback |
+| `getNpxCommand(args)` | Returns npx command with `meteor npx` fallback |
+| `getYarnCommand(args)` | Gets yarn command path |
+| `isYarnProject(opts)` | Detects yarn projects (yarn.lock, packageManager) |
+| `getMonorepoPath(opts)` | Detects monorepo root (workspaces, lerna, pnpm) |
+| `isMonorepo(opts)` | Boolean monorepo detection |
+
+### Process Management Module (`lib/process.js`)
+
+| Function | Description |
+|----------|-------------|
+| `spawnProcess(cmd, args, opts)` | Spawns process with streaming output, color preservation |
+| `stopProcess(proc, opts)` | Graceful termination with SIGTERM/SIGKILL fallback |
+| `isProcessRunning(proc)` | Checks if process is still running |
+| `isPortAvailable(port, host)` | Checks if port is free |
+| `waitForPort(port, opts)` | Waits for port availability with timeout |
+
+Options for `spawnProcess`: `env`, `cwd`, `detached`, `onStdout`, `onStderr`, `onExit`, `onError`
+
+### Meteor Configuration Module (`lib/meteor.js`)
+
+**Application Configuration:**
+
+| Function | Description |
+|----------|-------------|
+| `getMeteorAppDir()` | Gets application root directory |
+| `getMeteorAppPackageJson()` | Parses app's package.json |
+| `getMeteorAppConfig()` | Retrieves Meteor config from package.json or Plugin |
+| `getMeteorAppPort()` | Gets app port from environment |
+| `getMeteorAppConfigModern()` | Gets modern bundler configuration |
+| `isMeteorAppConfigModernVerbose()` | Checks verbose flag |
+| `hasMeteorAppConfigAutoInstallDeps()` | Auto-install deps flag |
+
+**Entry Points:**
+
+| Function | Description |
+|----------|-------------|
+| `getMeteorAppEntrypoints()` | Gets main/test modules for client/server |
+| `getMeteorInitialAppEntrypoints()` | Gets initial entry points with HTML detection |
+| `isMeteorAppTestModule()` | Checks if project is test module |
+| `setMeteorAppEntrypoints(opts)` | Sets entry points via environment variables |
+| `setMeteorAppIgnore(pattern)` | Sets file ignore patterns |
+| `setMeteorAppCustomScriptUrl(url)` | Sets custom script URLs |
+
+**Command Detection:**
+
+| Function | Description |
+|----------|-------------|
+| `isMeteorAppRun()` | Running in 'run' mode |
+| `isMeteorAppBuild()` | Running in 'build' or 'deploy' |
+| `isMeteorAppUpdate()` | Running in 'update' |
+| `isMeteorAppTest()` | In test mode |
+| `isMeteorAppTestFullApp()` | Test mode with full-app flag |
+| `isMeteorAppTestWatch()` | Test mode in watch mode |
+| `isMeteorAppNativeAndroid()` | Native Android mode |
+| `isMeteorAppNativeIos()` | Native iOS mode |
+| `isMeteorAppNative()` | Any native mode |
+| `isMeteorAppDevelopment()` | Development mode |
+| `isMeteorAppProduction()` | Production mode |
+| `isMeteorAppDebug()` | Debug mode |
+
+**Package Detection:**
+
+| Function | Description |
+|----------|-------------|
+| `isMeteorBlazeProject()` | Has blaze/blaze-html-templates |
+| `isMeteorBlazeHotProject()` | Blaze with hot reload |
+| `isMeteorCoffeescriptProject()` | Has CoffeeScript |
+| `isMeteorLessProject()` | Has Less CSS |
+| `isMeteorScssProject()` | Has SCSS/Sass |
+| `isMeteorTypescriptProject()` | Has TypeScript |
+| `isMeteorBundleVisualizerProject()` | Has bundle visualizer |
+| `isMeteorPackagesTest()` | test-packages command |
+
+**File Operations:**
+
+| Function | Description |
+|----------|-------------|
+| `getMeteorAppFilesAndFolders(opts)` | Scans app directory (recursive, with ignore) |
+| `getMeteorAppPackages()` | Lists all loaded packages |
+| `getMeteorEnvPackageDirs()` | Gets package directories from env vars |
+| `getMeteorToolsRequire(filePath)` | Requires module relative to Meteor tools |
+
+### Global State Module (`lib/global-state.js`)
+
+Maintains persistent state across file changes during development:
+
+```javascript
+import { getGlobalState, setGlobalState, removeGlobalState, clearGlobalState } from 'meteor/tools-core';
+
+setGlobalState('buildStartTime', Date.now());
+const startTime = getGlobalState('buildStartTime');
+```
+
+### Git Management Module (`lib/git.js`)
+
+| Function | Description |
+|----------|-------------|
+| `isGitRepository(dir)` | Checks if directory is git repo |
+| `gitignoreExists(dir)` | Checks .gitignore existence |
+| `ensureGitignoreExists(dir, entries)` | Creates .gitignore with initial entries |
+| `getMissingGitignoreEntries(dir, entries)` | Finds missing entries |
+| `addGitignoreEntries(dir, entries, ctx)` | Adds entries with context logging |
+
+### String Utilities (`lib/string.js`)
+
+| Function | Description |
+|----------|-------------|
+| `capitalizeFirstLetter(str)` | Capitalizes first character |
+| `shuffleString(str)` | Shuffles string characters |
+| `joinWithAnd(items, opts)` | Human-readable list ("a, b, and c") |
+
+---
+
+## Rspack Integration (`/packages/rspack`)
+
+Modern bundler integration using Rspack (Rust-based Webpack alternative).
+
+### Package Structure
+
+| File | Description |
+|------|-------------|
+| `lib/constants.js` | Default versions, global state keys, build contexts |
+| `lib/dependencies.js` | Dependency checking and auto-installation |
+| `lib/build-context.js` | Build directory management |
+| `lib/config.js` | Meteor configuration for Rspack |
+| `lib/processes.js` | Rspack process spawning |
+| `lib/compilation.js` | Compilation tracking |
+
+### Build Contexts
+
+| Context | Directory | Purpose |
+|---------|-----------|---------|
+| `RSPACK_BUILD_CONTEXT` | `_build` | Build output |
+| `RSPACK_ASSETS_CONTEXT` | `build-assets` | Static assets |
+| `RSPACK_CHUNKS_CONTEXT` | `build-chunks` | Chunk bundles |
+| `RSPACK_DOCTOR_CONTEXT` | `.rsdoctor` | Analysis/diagnostics |
+
+### Key Dependencies
+
+- `@rspack/core` ^1.7.1
+- `@meteorjs/rspack` ^0.3.56 (configuration logic)
+- `@rspack/plugin-react-refresh` ^1.4.3
+- `swc-loader` ^0.2.6
+
+### Integration with tools-core
+
+- Uses `getMeteorInitialAppEntrypoints()` for entry points
+- Uses command detection functions for build mode awareness
+- Uses process spawning and npm utilities
+
+---
+
+## TypeScript Compiler (`/packages/typescript`)
+
+Compiler plugin for TypeScript/TSX file compilation.
+
+**Registered Plugin:** `compile-typescript`
+
+**Supported Extensions:** `.ts`, `.tsx`
+
+**Implied Packages:** `modules`, `ecmascript-runtime`, `babel-runtime`, `promise`, `dynamic-import`
+
+**Features:**
+- Transpiles TypeScript before Babel processing
+- Supports client/server/legacy browser targets
+- Integrates with React Fast Refresh for HMR
+
+**Limitations:**
+- Per-file transpilation (no cross-file type analysis)
+- No tsconfig.json support (Meteor manages settings)
+- No type checking during compilation
+- No .d.ts generation
+
+---
+
+## WebApp & Express (`/packages/webapp`)
+
+HTTP server integration using Express.js 5.x framework.
+
+### Key APIs
+
+```javascript
+import { WebApp } from 'meteor/webapp';
+
+// Middleware registration
+WebApp.connectHandlers.use('/api', myMiddleware);
+WebApp.handlers.use(compression());
+
+// Direct Express access
+WebApp.expressApp.get('/health', (req, res) => res.send('OK'));
+
+// Server instance
+WebApp.httpServer;
+
+// Hooks
+WebApp.onListening(() => console.log('Server ready'));
+```
+
+### Express Exports
+
+| Property | Description |
+|----------|-------------|
+| `WebApp.connectHandlers` | Express middleware registry (legacy name) |
+| `WebApp.handlers` | Current middleware registry |
+| `WebApp.rawConnectHandlers` | Raw Express handlers |
+| `WebApp.expressApp` | Direct Express app instance |
+| `WebApp.httpServer` | HTTP server instance |
+| `WebApp.express` | Express module export |
+
+**Dependencies:** express@5.1.0, cookie-parser@1.4.6, compression@1.7.4, errorhandler@1.5.1
diff --git a/.github/skills/packages/SKILL.md b/.github/skills/packages/SKILL.md
new file mode 100644
index 0000000000..4c0b1b467e
--- /dev/null
+++ b/.github/skills/packages/SKILL.md
@@ -0,0 +1,152 @@
+---
+name: packages
+description: Use when exploring the package ecosystem, finding which package handles a feature, understanding package relationships, or adding dependencies. Lists all core packages by domain.
+---
+
+# Core Packages
+
+Overview of Meteor's package ecosystem organized by domain.
+
+## Authentication & Accounts
+
+| Package | Description |
+|---------|-------------|
+| `accounts-base` | Foundation for the user account system |
+| `accounts-password` | Password-based authentication |
+| `accounts-passwordless` | Magic-link/token-based authentication |
+| `accounts-2fa` | Two-factor authentication support |
+| `accounts-ui` / `accounts-ui-unstyled` | Pre-built UI components for auth |
+| `accounts-oauth` | OAuth protocol support |
+| `oauth` / `oauth1` / `oauth2` | OAuth implementation |
+| `oauth-encryption` | Encrypted OAuth token storage |
+| `service-configuration` | OAuth provider configuration |
+
+**Social Login Providers:**
+- `accounts-facebook`, `accounts-github`, `accounts-google`
+- `accounts-twitter`, `accounts-meetup`, `accounts-weibo`
+- `accounts-meteor-developer`
+
+## Data & Database
+
+| Package | Description |
+|---------|-------------|
+| `mongo` | MongoDB integration and collection API |
+| `minimongo` | Client-side MongoDB emulation |
+| `mongo-id` | MongoDB ObjectID generation |
+| `mongo-livedata` | Reactive MongoDB queries |
+| `npm-mongo` | MongoDB Node.js driver wrapper |
+| `mongo-dev-server` | Development MongoDB server |
+| `ddp` | Distributed Data Protocol meta-package |
+| `ddp-common` | Shared DDP utilities |
+| `ddp-client` | DDP client implementation |
+| `ddp-server` | DDP server implementation |
+| `ddp-rate-limiter` | Rate limiting for DDP methods/subscriptions |
+| `ejson` | Extended JSON serialization |
+
+## Build System & Compilation
+
+| Package | Description |
+|---------|-------------|
+| `babel-compiler` | JavaScript transpilation via Babel |
+| `babel-runtime` | Babel runtime helpers |
+| `ecmascript` | ECMAScript 2015+ support |
+| `ecmascript-runtime` | ES6+ runtime polyfills |
+| `typescript` | TypeScript compilation support |
+| `modules` | ES modules system |
+| `modules-runtime` | Module runtime implementation |
+| `modules-runtime-hot` | Hot module reloading runtime |
+| `hot-code-push` | Live code updates |
+| `hot-module-replacement` | HMR support |
+| `rspack` | Rspack bundler integration |
+| `boilerplate-generator` | HTML boilerplate generation |
+| `dynamic-import` | Dynamic `import()` support |
+| `caching-compiler` | Build cache management |
+
+## Minification & Assets
+
+| Package | Description |
+|---------|-------------|
+| `minifier-js` | JavaScript minification (terser) |
+| `minifier-css` | CSS minification |
+| `standard-minifier-js` | Default JS minifier package |
+| `standard-minifier-css` | Default CSS minifier package |
+| `standard-minifiers` | Meta-package for minifiers |
+| `static-html` | Static HTML file processing |
+
+## Web & Server
+
+| Package | Description |
+|---------|-------------|
+| `webapp` | HTTP server and request handling |
+| `webapp-hashing` | Asset fingerprinting |
+| `reload` | Client-side app reload mechanism |
+| `reload-safetybelt` | Reload failure recovery |
+| `autoupdate` | Automatic client updates |
+| `browser-policy` | Content Security Policy |
+| `force-ssl` | HTTPS enforcement |
+| `allow-deny` | Collection permission rules |
+| `fetch` | HTTP Fetch API polyfill |
+| `routepolicy` | Route-based policies |
+
+## Client-Side Utilities
+
+| Package | Description |
+|---------|-------------|
+| `tracker` | Reactive dependency tracking |
+| `reactive-var` | Single reactive value |
+| `reactive-dict` | Reactive key-value store |
+| `session` | Client-side session storage |
+| `localstorage` | LocalStorage wrapper |
+| `socket-stream-client` | WebSocket client |
+| `random` | Cryptographic random generation |
+| `check` | Runtime type checking |
+| `underscore` | Utility library |
+| `base64` | Base64 encoding/decoding |
+| `diff-sequence` | Array diffing algorithm |
+| `id-map` | ID-based mapping |
+| `ordered-dict` | Ordered dictionary |
+
+## Testing (6 packages)
+
+| Package | Description |
+|---------|-------------|
+| `tinytest` | Meteor's built-in test framework |
+| `tinytest-harness` | Test harness utilities |
+| `test-helpers` | Testing utility functions |
+| `test-in-browser` | Browser-based test runner |
+| `test-in-console` | Console-based test runner |
+
+## Context & Roles
+
+| Package | Description |
+|---------|-------------|
+| `context` | Request context management (AsyncLocalStorage) |
+| `roles` | User roles and permissions system |
+
+## Deprecated Packages (`packages/deprecated/`)
+
+40+ legacy packages maintained for backward compatibility:
+- UI libraries: `amplify`, `backbone`, `d3`, `handlebars`
+- Legacy OAuth: `facebook`, `github`, `google` (use `accounts-*` instead)
+- Config UIs: `*-config-ui` packages
+- Others: `jquery-history`, `jshint`, `jsparse`, `deps` (use `tracker`)
+
+## Development-Only Packages
+
+| Package | Description |
+|---------|-------------|
+| `autopublish` | Auto-publish all collections (remove in production) |
+| `insecure` | Allow all database writes (remove in production) |
+
+## NPM Packages (`/npm-packages`)
+
+Packages published to npm for external use:
+
+| Package | npm Name | Description |
+|---------|----------|-------------|
+| `meteor-babel` | `@meteorjs/babel` | Babel wrapper for ES2015+ transpilation |
+| `babel-preset-meteor` | `@meteorjs/babel-preset-meteor` | Babel preset with Meteor-specific transforms |
+| `meteor-rspack` | `@meteorjs/rspack` | Rspack configuration builder |
+| `meteor-promise` | `meteor-promise` | ES6 Promise with Fiber support |
+| `meteor-node-stubs` | `meteor-node-stubs` | Node.js core module polyfills for browser |
+| `eslint-plugin-meteor` | `eslint-plugin-meteor` | Meteor-specific ESLint rules |
diff --git a/.github/skills/testing/SKILL.md b/.github/skills/testing/SKILL.md
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--- /dev/null
+++ b/.github/skills/testing/SKILL.md
@@ -0,0 +1,144 @@
+---
+name: testing
+description: Use when writing tests, debugging test failures, running the test suite, or setting up test infrastructure. Covers self-test, package tests, and modern E2E tests.
+---
+
+# Testing
+
+Test patterns, commands, and utilities for the Meteor codebase.
+
+## Test Commands
+
+```bash
+# CLI self-tests
+./meteor self-test                           # Run all CLI tests
+./meteor self-test "test name"               # Run specific test
+./meteor self-test --list                    # List available tests
+./meteor self-test --exclude "^[a-b]"        # Exclude tests by regex
+./meteor self-test --retries 0               # Skip retries in development
+
+# Package tests (TinyTest — view results at http://localhost:3000)
+./meteor test-packages                       # Test all core packages
+./meteor test-packages mongo                 # Test specific package
+TINYTEST_FILTER="collection" ./meteor test-packages  # Filter specific tests
+
+# Package tests in console (headless via Puppeteer)
+PUPPETEER_DOWNLOAD_PATH=~/.npm/chromium ./packages/test-in-console/run.sh
+
+# Modern E2E tests (Jest + Playwright)
+npm run install:modern                       # Install dependencies
+npm run test:modern                          # Run all E2E tests
+npm run test:modern -- -t="React"            # Run specific test
+```
+
+## Modern E2E Tests (`tools/modern-tests/`)
+
+Jest + Playwright suite for verifying modern bundler integrations (rspack). Tests cover framework skeletons and build scenarios.
+
+**Test apps:** `apps/{react,vue,svelte,solid,blaze,typescript,babel,coffeescript,monorepo}`
+
+## Test Helpers Package (`packages/test-helpers`)
+
+Comprehensive testing utilities for Meteor applications.
+
+### Async Testing
+
+```javascript
+import { testAsyncMulti, simplePoll, waitUntil } from 'meteor/test-helpers';
+
+// Wait for condition
+await waitUntil(() => someCondition, { timeout: 5000, interval: 100 });
+
+// Poll until ready
+simplePoll(() => isReady(), successCallback, failCallback);
+```
+
+### DOM/UI Testing
+
+```javascript
+import { clickElement, simulateEvent, canonicalizeHtml, renderToDiv } from 'meteor/test-helpers';
+
+clickElement(button);
+simulateEvent(input, 'keydown', { keyCode: 13 });
+const normalized = canonicalizeHtml(html);
+```
+
+### Connection Testing
+
+```javascript
+import { makeTestConnection, captureConnectionMessages } from 'meteor/test-helpers';
+
+const conn = makeTestConnection(clientId);
+const messages = captureConnectionMessages(server);
+```
+
+### Utilities
+
+| Function | Description |
+|----------|-------------|
+| `SeededRandom` | Predictable random for deterministic tests |
+| `try_all_permutations()` | Test all permutations of inputs |
+| `withCallbackLogger()` | Track callback invocations |
+| `mockBehaviours()` | Behavior mocking |
+
+## Tinytest (`packages/tinytest`)
+
+Meteor's built-in test framework.
+
+```javascript
+Tinytest.add('my test', function (test) {
+  test.equal(1 + 1, 2);
+  test.isTrue(true);
+  test.throws(function () { throw new Error(); });
+});
+
+Tinytest.addAsync('async test', async function (test) {
+  const result = await asyncOperation();
+  test.equal(result, expected);
+});
+```
+
+## Environment Variables
+
+| Variable | Description |
+|----------|-------------|
+| `TEST_METADATA` | Test configuration JSON |
+| `METEOR_TEST_PACKAGES` | Packages to test |
+
+## Debug Commands
+
+```bash
+# Verbose build output
+METEOR_DEBUG_BUILD=1 ./meteor run
+
+# Profile build performance
+METEOR_PROFILE=1 ./meteor build
+
+# Force rebuild
+./meteor reset && ./meteor run
+
+# Debug Meteor tool with Chrome inspector
+TOOL_NODE_FLAGS="--inspect-brk" ./meteor
+```
+
+## Writing Package Tests
+
+In `package.js`:
+
+```javascript
+Package.onTest(function(api) {
+  api.use(['tinytest', 'test-helpers', 'my-package']);
+  api.addFiles('my-package-tests.js');
+});
+```
+
+In `my-package-tests.js`:
+
+```javascript
+import { MyPackage } from 'meteor/my-package';
+
+Tinytest.add('MyPackage - basic functionality', function (test) {
+  const result = MyPackage.doSomething();
+  test.equal(result, expected);
+});
+```
diff --git a/AGENTS.md b/AGENTS.md
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+++ b/AGENTS.md
@@ -0,0 +1,60 @@
+# Meteor
+
+Full-stack JavaScript platform for modern web and mobile applications.
+
+## Commands
+
+```bash
+./meteor run                                 # Run from source
+./meteor create my-app                       # Create app
+./meteor self-test                           # CLI tests
+./meteor test-packages ./packages/<name>     # Package tests
+npm run test:modern                          # E2E tests (Jest + Playwright)
+```
+
+## Structure
+
+```
+packages/          # Core Meteor packages (~100+)
+tools/             # CLI & build system (Isobuild)
+npm-packages/      # Published @meteorjs/* packages
+scripts/           # Build & release automation
+```
+
+## Key Entry Points
+
+| Task | Location |
+|------|----------|
+| CLI commands | `tools/cli/commands.js` |
+| Build system | `tools/isobuild/bundler.js` |
+| Package lookup | `packages/<name>/package.js` |
+| Modern bundler | `packages/rspack/`, `packages/tools-core/` |
+
+## Skills
+
+Load these for detailed context on specific topics:
+
+| Skill | When to use |
+|-------|-------------|
+| [codebase](.github/skills/codebase/SKILL.md) | Build system, CLI, isobuild, tools/ directory |
+| [conventions](.github/skills/conventions/SKILL.md) | Writing packages, CLI commands, code patterns |
+| [testing](.github/skills/testing/SKILL.md) | Writing tests, debugging failures, test infrastructure |
+| [packages](.github/skills/packages/SKILL.md) | Finding packages by feature, understanding dependencies |
+| [modern-tools](.github/skills/modern-tools/SKILL.md) | tools-core utilities, rspack, modern integrations |
+| [ai-context](.github/skills/ai-context/SKILL.md) | Creating, updating, or maintaining AI documentation files |
+
+## Package Domains
+
+| Category | Packages |
+|----------|----------|
+| Auth | `accounts-base`, `accounts-password`, `accounts-oauth` |
+| Database | `mongo`, `minimongo`, `ddp-server`, `ddp-client` |
+| Build | `babel-compiler`, `ecmascript`, `typescript`, `rspack` |
+| Web | `webapp`, `autoupdate`, `reload` |
+| Reactivity | `tracker`, `reactive-var`, `reactive-dict` |
+
+## Notes
+
+- `docs/` and `guide/` are the public documentation website, not agent context
+- `v3-docs/` contains Meteor 3.x documentation
+- See [DEVELOPMENT.md](DEVELOPMENT.md) for contributor setup
diff --git a/CLAUDE.md b/CLAUDE.md
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--- /dev/null
+++ b/CLAUDE.md
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+Read [AGENTS.md](AGENTS.md) before starting any task.
+
+## Skills
+
+Load these for detailed context on specific topics:
+
+| Skill | When to use |
+|-------|-------------|
+| [codebase](.github/skills/codebase/SKILL.md) | Build system, CLI, isobuild, tools/ directory |
+| [conventions](.github/skills/conventions/SKILL.md) | Writing packages, CLI commands, code patterns |
+| [testing](.github/skills/testing/SKILL.md) | Writing tests, debugging failures, test infrastructure |
+| [packages](.github/skills/packages/SKILL.md) | Finding packages by feature, understanding dependencies |
+| [modern-tools](.github/skills/modern-tools/SKILL.md) | tools-core utilities, rspack, modern integrations |
+| [ai-context](.github/skills/ai-context/SKILL.md) | Creating, updating, or maintaining AI documentation files |