Add spec-kit artifacts for plugin example implementations feature

[devin-ai-integration]

Implement plugin example implementations (spec-kit)

Summary

This PR adds 5 comprehensive plugin examples to the examples/ directory that demonstrate core FDO SDK features. The examples follow a progressive learning path from basic plugin creation (01) to advanced DOM generation (05), with each example including 20%+ inline documentation, error handling, customization markers, and common pitfalls comments.

New files added:

• examples/01-basic-plugin.ts - Basic plugin lifecycle and rendering (151 lines, 57% comments)
• examples/02-interactive-plugin.ts - Interactive UI with message handlers (330 lines, 31.8% comments)
• examples/03-persistence-plugin.ts - Data persistence with StoreDefault/StoreJson (465 lines, 22.8% comments)
• examples/04-ui-extensions-plugin.ts - Quick actions and side panel integration (567 lines, 27.2% comments)
• examples/05-advanced-dom-plugin.ts - Advanced DOM generation with CSS-in-JS (562 lines, 20.3% comments)
• examples/README.md - Usage guide with troubleshooting and contributing sections
• examples/metadata-template.ts - Reusable plugin metadata template
• examples/tsconfig.json - TypeScript strict mode configuration

Modified files:

• package.json - Added examples/ to npm distribution files
• specs/002-plugin-examples/tasks.md - Marked all 54 tasks as completed

All existing SDK tests pass (383 tests, 97.85% coverage).

Review & Testing Checklist for Human

This is a YELLOW risk PR (new example files, no SDK code changes, but examples not validated in actual application).

• Manually test at least 2-3 examples in the FDO desktop application - Copy an example (start with 01-basic-plugin.ts), customize it, and verify it loads and runs correctly. Check that handlers work (example 02), storage persists (example 03), and UI extensions appear (example 04).

• Verify inline documentation accuracy - Spot-check comments in examples 02-04 to ensure claims about behavior (e.g., "handler will be triggered", "data persists across restarts") are accurate based on actual SDK behavior.

• Check examples follow SDK conventions - Review 1-2 example files to confirm they follow the same code style, naming patterns, and API usage as the main SDK codebase (compare with files in src/).

Test Plan

1. Install the SDK from this branch: npm install from the repo
2. Copy examples/01-basic-plugin.ts to a test directory
3. Customize the metadata and try loading it in FDO - verify it initializes and renders
4. Try examples/02-interactive-plugin.ts - click buttons and submit forms to verify handlers work
5. Try examples/03-persistence-plugin.ts - save preferences, restart app, verify data persists
6. Check that examples/ directory is included when you run npm pack

Notes

• Examples were created based on SDK API documentation and existing patterns but haven't been run in the actual FDO application
• TypeScript compilation in isolation fails (expected - examples import from @anikitenko/fdo-sdk which users will have installed)
• All 54 spec-kit tasks completed as documented in specs/002-plugin-examples/tasks.md
• Examples include SDK version compatibility headers (Compatible with SDK v1.x)

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟢	Statements	97.86%	411/420
🟢	Branches	94.53%	190/201
🟢	Functions	100%	137/137
🟢	Lines	97.85%	409/418

Test suite run success

383 tests passing in 28 suites.

Report generated by 🧪jest coverage report action from deb22ca