[Refactor] Consolidate integration tool approval waits

[roomote-roomote]

​Created by Roomote. View the task or mention @roomote-roomote for follow-up asks.

What changed

• Added one SDK approval-wait contract for polling cadence, terminal status classification, deadlines, cancellation, and optional one-shot claiming.
• Moved the API fallback, worker relay, and Fast session bridge onto that contract while keeping request creation, claims, notifications, and runtime replies at their existing boundaries.
• Added focused lifecycle coverage for rejection and invalid terminal states, expiry, abort timing, and approval consumption.

Why this change was made

The three integration approval runtimes had independently accumulated the same wait state machine. Centralizing the shared lifecycle prevents timeout, abort, and terminal-status behavior from drifting while leaving security-sensitive runtime ownership explicit.

Impact

There is no intended user-facing behavior change. Integration tool approvals keep failing closed and remain one-use, with a smaller lifecycle surface for future fixes.

[roomote-community]

No code issues found. See task

_{Reviewed d6e162b}