Add MCP tools for log inspection and Script API/XSD docs

[clavery]

Summary

• Logs MCP tools for the B2C Commerce instance via WebDAV: logs_list_files, logs_get_recent, plus a watch lifecycle (logs_watch_start / logs_watch_poll / logs_watch_stop / logs_watch_list) that buffers entries between polls so an agent doesn't miss logs produced between tool calls.
• Docs MCP tools over the bundled Script API and XSD corpora: docs_search, docs_read, docs_list, docs_schema_search, docs_schema_read, docs_schema_list. No instance auth required.
• New DIAGNOSTICS toolset that groups the script debugger and log tools. Existing debug tools are re-tagged onto DIAGNOSTICS in addition to their current CARTRIDGES / SCAPI assignments.
• SDK promotion: log filter helpers (parseSinceTime, filterBy*, matchesLevel, matchesSearch) moved from packages/b2c-cli/src/utils/logs into @salesforce/b2c-tooling-sdk/operations/logs so the MCP package can reuse them. CLI re-exports from the SDK; existing CLI tests and behavior unchanged.
• New LogWatchRegistry on ServerContext (mirrors DebugSessionRegistry): UUID watch ids, hostname-level dedup, capped buffer with eviction counter, idle TTL cleanup, poll waiters with timeout. New docs pages for both tool families and sidebar updates.

Tool reference

Logs (CARTRIDGES, DIAGNOSTICS, SCAPI)

Tool	Input	Behavior
logs_list_files	prefixes?, sort_by?, sort_order?	One-shot WebDAV listing
logs_get_recent	prefixes?, count?, since?, level?, search?	One-shot fetch with client-side filters
logs_watch_start	prefixes?, last_entries?, poll_interval_ms?, level?, search?	Starts a buffered tail; returns watch_id
logs_watch_poll	watch_id, timeout_ms?, max_entries?	Drains buffer; blocks up to timeout_ms if empty
logs_watch_stop	watch_id	Stops tail, releases registry slot
logs_watch_list	—	Lists active watches (recovery aid)

Docs (all toolsets)

docs_search / docs_read / docs_list for Script API; docs_schema_search / docs_schema_read / docs_schema_list for XSD.

Test plan

• pnpm run typecheck:agent
• pnpm run lint:agent
• pnpm --filter @salesforce/b2c-tooling-sdk run test:agent (1722 passing — verifies log filter helper promotion didn't break SDK or CLI usage)
• pnpm --filter @salesforce/b2c-cli run test:agent (1218 passing — verifies CLI still consumes filter helpers via SDK re-export)
• pnpm --filter @salesforce/b2c-dx-mcp run test:agent (767 passing — includes new log-watch-registry.test.ts, logs-tools.test.ts, docs-tools.test.ts)
• Manual smoke against a sandbox via MCP inspector:
  • logs_list_files returns files
  • logs_get_recent {prefixes: ["error"], count: 5} returns parsed entries
  • logs_watch_start → trigger storefront error → logs_watch_poll returns the entry → logs_watch_stop cleans up
  • docs_search ProductMgr → docs_read dw.catalog.ProductMgr → markdown body
  • docs_schema_list → docs_schema_read catalog → XSD content
• pnpm run docs:dev — sidebar shows Logs under Diagnostics + new Documentation group; both new pages render