feat: enterprise M365 Copilot (Cowork) driver + OpenAI bridge routing

[Rithmatist]

What

Adds a headless driver for work / school (Entra ID) accounts, which Microsoft redirects off consumer Copilot to the enterprise Microsoft 365 Copilot ("Cowork") — a different backend the existing driver can't speak.

copilot/m365 mints resource tokens via a public-client refresh-token grant (bootstrapped once interactively, then fully headless), sends prompts to the Copilot Studio "Aether" runtime, and reads the streamed reply off a Trouter (Teams Socket.IO) push channel after registering the endpoint. Reverse-engineered from live captures (tests/capture_*.py).

Server

• New model copilot-work → M365 driver; copilot → consumer (unchanged).
• Client title-generation meta-call answered locally (saves a full upstream turn).
• Server binds instantly (dropped the blocking startup browser pre-warm).
• Text tool-call bridging (server/tool_calls.py) so OpenAI-compatible agent clients get executable tool_calls.

Extras

• work-chat.ps1 — launches OpenClaude against the bridge as a local coding agent.
• New README section "Usage 3: Work / school account + coding agents".
• 44 unit tests (tests/test_m365_*.py, tests/test_tool_calls.py), all green.

Notes

• Work turns are slow (~20–60s each — the Cowork backend, not the bridge); the server serializes upstream calls.
• Requires an M365 Copilot–licensed tenant that permits token-based access; some tenants block non-interactive tokens via conditional access.
• No secrets committed: session tokens/logs are gitignored; test fixtures use placeholder GUIDs.

🤖 Generated with Claude Code