feat(compute): extended tool capability tiers

**Context:** ROADMAP.md → Security → Tool capability tiers
**Related:** #422 (HITL elevation), #429, #246

---

## Component

CDK / infrastructure

## Describe the feature

Opt-in **extended** tool profile per repo: MCP servers, plugins, and additional Gateway-mediated tools beyond the default minimal surface. Enforced at **Gateway** and **Cedar policy** layers.

## Use case

Default minimal tool surface is safe but limiting. Power users need MCP integrations with explicit opt-in and policy gates—not silent expansion.

## Proposed solution

1. Blueprint flag: `tool_profile: minimal | extended`.
2. Gateway allowlist of tool names/MCP servers per profile.
3. Cedar policies for extended-only actions.
4. Audit when profile is elevated mid-task (#422).
5. Document in `docs/design/COMPUTE.md`.

## Other information

- #422 covers runtime elevation via HITL; this covers **static profile definition**.
- Pairs with **MCP supply-chain controls** (#429).
- Design context: `docs/design/COMPUTE.md`, `docs/design/CEDAR_HITL_GATES.md`.

- [ ] This might be a breaking change

Inizia leggendo docs/design/COMPUTE.md e docs/design/CEDAR_HITL_GATES.md, quindi esamina le issue correlate #422, #429 e #246 per separare i profili statici dall’elevazione a runtime e dai controlli della supply chain. Il lavoro è completo quando il blueprint flag, la Gateway allowlist, i Cedar gates, il elevation audit behavior e la documentazione sono definiti e implementati senza ampliare silenziosamente il profilo predefinito.

Scritto dal modello di indicizzazione a partire dal testo della issue.