v3.21.0 - Forge-Master CTO defaults + audit tool

v3.21.0 - Forge-Master CTO defaults + audit tool

Phase-43 Forge-Master CTO defaults + audit tool. Adds forge_master_audit MCP tool (bounded CTO audit report) and pforge audit CLI. Three lane-specific system-prompt overlays (advisory-cto, build-interviewer, troubleshoot-sre). Four defaults flipped to CTO-friendly: quorumAdvisory=auto, autoEscalate=true, l3Enabled=true, observer.enabled=true. + @baseline philosophy alias in .forge.json. Restored 17 read-only tools to pforge-master BASE_ALLOWLIST (#149). CI parity guard for allowlist <-> TOOL_NAMES drift. Refreshed docs/capabilities.md|.html + manual/forge-master.html for 105-tool surface. Repairs pforge-mcp/package.json drift from 3.20.0 (same pattern as v3.17.0 recovery).