[API] Expose capture_pprof as an MCP tool (capture_agent_pprof)

[ToddHebebrand]

Description

PR #2394 (#2389) adds the capture_pprof agent command (heap/goroutine profiles returned base64 via the command result, no listener). Making it AI-invokable was deliberately deferred because MCP tool registration requires a multi-site sweep, and partial registration is a known drift trap (the AI gate reads TWO maps — a tool registered in one but not the other silently misbehaves).

Proposed Fix

Register capture_agent_pprof following the set_agent_log_level pattern (apps/api/src/services/aiToolsAgentLogs.ts:150-230), covering ALL registration sites in one PR:

• SDK tool map / registry hub
• guardrails permission map AND rate-limit map (both — dual-map drift)
• approval switch (approval-gated, Tier-2, like other device-touching diagnostics)
• tool schemas
• web tierConfig (×3 sites)

Result should surface profile metadata (sizes, capture time) and hand back the artifact in a way the chat UI can offer for download, not a giant inline base64 blob in the transcript.

Blocked On

PR #2394 — the agent command and CAPTURE_PPROF command type only exist on that branch.

Affected Files

• apps/api/src/services/aiToolsAgentLogs.ts (or a new aiToolsDiag file per the hub/per-domain pattern)
• guardrails + tierConfig registration sites

Refs #2389.

[ToddHebebrand]

PR #2409 implements this: capture_agent_pprof registered at all sites in one pass (tool implementation, SDK tool map + registration, guardrails permission and rate-limit maps, approval description, tool schemas, system prompt, web tierConfig ×3 — the parity test passes with no new legacy-gap entries).

Two things the PR fixes beyond registration, found during review, that also affected the #2394 human path:

• Result-ingest secret redaction was statistically corrupting large base64 stdout — capture_pprof results are now stored byte-for-byte on both ingest legs.
• The single-command GET now passes profile stdout through (history redaction previously made the profiles unretrievable at all), and the heartbeat/REST result leg got a body-limit carve-out so multi-MB results don't 413 into fake timeouts.

The tool returns metadata only (sizes, capture time, runtime gauges incl. goroutine count) plus a retrieval pointer — no base64 in the chat transcript.