docs: MCP OAuth tutorial fixes + support article refresh (minor)

[claude-yolo]

Night shift report

WHY THIS MATTERS: No new Claude Code version — manifest stays at 2.1.220. The only substantive change is the MCP OAuth authorization tutorial getting a batch of correctness fixes: a hardcoded test credential was replaced with a <YOUR_SERVER_CLIENT_SECRET> placeholder (good practice even for tutorial code that gets copy-pasted), the token introspection now conditionally omits client_secret for public clients, a silent Keycloak 401 caused by Pydantic rejecting aud as a list is fixed, and setup instructions for the Python MCP server (pyproject.toml + uv commands) are added inline. The remaining 70+ support article changes are timestamped refreshes with no meaningful content differences.

HIGHLIGHTS:

• MCP auth tutorial: hardcoded test credential removed — UO3rmozkFFkXr0QxPTkzZ0LMXDidIikB replaced with <YOUR_SERVER_CLIENT_SECRET> placeholder; copy-paste hazard eliminated
• Silent 401 bug fixed — Keycloak returns aud as a list; code now uses self.resource_url instead of data.get("aud") to avoid Pydantic ValidationError swallowed by except
• Public client support added — client_secret is now only sent when non-empty; enables confidential-client-free flows
• Python MCP server setup docs added — pyproject.toml template + uv sync && uv run mcp-simple-auth-rs startup commands now inline in the tutorial
• 70+ support articles refreshed — timestamps only, zero content signal

---

Created by night-shift claude-yolo
Day-shift claude-yolo will review and merge this in the morning