Update documentation for agentic mode

[RichardAtCT]

Summary

• README.md: Rewritten for agentic-first presentation — new demo, modes section (agentic default vs classic), event-driven automation section, updated config and features
• CLAUDE.md: Updated architecture with orchestrator routing, webhook/scheduler flows, new key directories (events, api, scheduler, notifications), split "Adding a New Bot Command" for agentic vs classic
• CHANGELOG.md: Added agentic platform entry (MessageOrchestrator, event bus, webhook API, scheduler, notifications, DB migration 3), marked TODO-7 complete
• SECURITY.md: Removed stale "Planned Security Features" code stubs, added webhook authentication section (GitHub HMAC-SHA256, Bearer token, deduplication), updated production checklist
• docs/configuration.md: Added agentic platform config section (AGENTIC_MODE, ENABLE_API_SERVER, API_SERVER_PORT, GITHUB_WEBHOOK_SECRET, WEBHOOK_API_SECRET, ENABLE_SCHEDULER, NOTIFICATION_CHAT_IDS), updated feature flags list
• docs/setup.md: Added agentic platform setup (GitHub webhook config steps, generic webhook curl example, scheduler and notification setup)
• docs/project-overview.md: Added agentic mode as default, event-driven architecture to components and data flow
• Deleted 12 stale planning docs: todo-1 through todo-9, high-level-todo, implementation-summary, FEATURE_IMPLEMENTATION_SUMMARY

Test plan

• All config variable names verified against src/config/settings.py and src/config/features.py
• All file path references verified against actual source tree
• No code changes — docs only (-584/+7981 lines, 19 files)
• Internal links between docs are consistent

[RichardAtCT]

PR Review
Reviewed head: e433bbbbe4e038566315536426e85648ca4af0cc

Summary

• This is a substantial docs refresh that aligns the project narrative around agentic mode as default and adds practical setup guidance for webhooks/scheduler/notifications.
• Cleanup of old planning docs reduces noise and makes the docs set feel more “current state” oriented.

What looks good

• README.md now presents a clearer “how to use this in practice” flow and better separates agentic vs classic behavior.
• docs/configuration.md and docs/setup.md now expose the key env flags for the new platform surface (AGENTIC_MODE, ENABLE_API_SERVER, ENABLE_SCHEDULER, webhook secrets, notification chat IDs).
• SECURITY.md webhook auth section is a meaningful upgrade over placeholder/planned text.

Issues / questions

1. [Nit] PR body — the “No code changes” stats line appears inverted (-584/+7981), while the actual PR stats show mostly deletions (old docs removed) plus targeted additions. Worth correcting to avoid reviewer confusion.

Suggested tests (if needed)

• N/A for runtime behavior (docs-only).
• Optional: run a lightweight docs link check in CI to prevent broken references after deleting the old TODO docs.

Verdict

• ✅ Ready to merge