feat: Add real chat comparison demos

[konard]

Fixes #3.

Summary

• Replaced the fake/read-only gallery behavior with real package integrations for ChatScope, React Chat Elements, and Deep Chat, plus exact source-code snippets for Stream, Sendbird, CometChat, TalkJS, and assistant-ui where hosted credentials or runtime adapters are required.
• Added a working shared markdown composer so each demo can accept and render user replies instead of showing static fixtures only.
• Added code-cost, render-time, DOM-node, heap, maintenance, license, release, and repository metadata to the catalog and assistant-facing snapshot APIs.
• Rebuilt docs/case-studies/issue-3 with issue/PR data, npm metadata, GitHub repository snapshots, and research notes for the libraries compared.
• Updated docs, CI screenshot artifact paths, and added a minor changeset for the new comparison behavior.

Reproduction and verification

• Regression coverage: tests/e2e/chat-demos.e2e.js now types markdown into [data-testid="chat-composer-input"], submits it, and asserts the transcript grows and renders the submitted content.
• Source coverage: e2e now verifies every demo exposes exact source code containing real imports.
• Manual browser check: opened http://127.0.0.1:5173/, selected ChatScope, submitted **Browser check** source renders and input submits., verified a fourth message appeared, and checked browser console warnings/errors were zero.

Screenshot

Checks

• npm test
• npm run demo:build (passes; Vite reports the expected large combined chunk warning from bundling several real chat UI packages)
• npm run test:e2e
• npm run lint
• npm run format:check
• npm run check
• npm run changeset:status
• npm ls --depth=0
• git diff --check

[konard]

Working session summary

Implemented, pushed, and marked PR #4 ready for review:

#4

What changed: the demo gallery now uses real chat UI package imports, has a working markdown composer, exposes exact source snippets/code cost/metrics/maintenance metadata, and includes issue-3 research data plus a committed screenshot.

Verification passed locally:
npm test, npm run demo:build, npm run test:e2e, npm run lint, npm run format:check, npm run check, npm run changeset:status, npm ls --depth=0, git diff --check.

GitHub CI is green for commit 41d1b64: Broken Link Checker, Chat demo pages, and Checks and release all completed successfully. The local demo server is running at http://127.0.0.1:5173/ with logs in logs/demo-dev.log.

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This summary was automatically extracted from the AI working session output.

[konard]

🤖 Solution Draft Log

This log file contains the complete execution trace of the AI solution draft process.

💰 Cost estimation:

• Model: GPT-5.5
• Provider: OpenAI
• Public pricing estimate: $20.842544

📊 Context and tokens usage:

• 389.1K / 1.1M (37%) input tokens, 51.7K / 128K (40%) output tokens

Total: (389.1K + 14.6M cached) input tokens, 51.7K output tokens, $20.842544 cost

🤖 Models used:

• Tool: OpenAI Codex
• Requested: gpt-5.5
• Model: GPT-5.5 (gpt-5.5)

📎 Log file uploaded as Repository (84230KB)

• View complete solution draft log

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Now working session is ended, feel free to review and add any feedback on the solution draft.

[konard]

🎉 Auto-merged

This pull request has been automatically merged by hive-mind.

• All CI checks have passed

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Auto-merged by hive-mind with --auto-merge flag