fix(resilience): widen combo cooldown-wait gate to all strategies

[hartmark]

Summary

Fixes #8541.

isComboCooldownWaitEligible() in comboConfig.ts was restricted to quota-share and auto strategies, but the cooldown-wait decision body in combo.ts, its inline comments, and the priority test all describe universal behavior per #7301. The restriction arrived in #8213 when extracting the predicate — incidental to the timeout-floor coupling, not a deliberate scope reduction.

Changes

• open-sse/services/comboConfig.ts: Remove strategy check from isComboCooldownWaitEligible — now returns comboCooldownWait.enabled for all strategies (the _strategy param is kept for API compatibility)
• tests/unit/combo-config.test.ts: Update test to assert all strategies are eligible when the feature is enabled; update resolveComboTargetTimeoutMsForCombo test to expect raised floor for all strategies
• tests/unit/serial/combo-quota-share-cooldown-wait-timing.test.ts: Status assertion changes from 429→403 in the quota_exhausted test because the lockout path now runs for priority strategy (the security property — no wait+redispatch on quota_exhausted — still holds)

Verification

• combo-config.test.ts: 44/44 pass
• combo-quota-share-cooldown-wait-timing.test.ts: 4/4 pass (including the previously failing priority test)
• ESLint: clean
• lint-staged: passed on commit

[hartmark]

Closing in favor of #8559 — the reporter's PR is more thorough. It fixes both the gate AND the entry condition in combo.ts (decouples the cooldown-wait decision from whichever target last overwrote status), plus updates UI strings, docs, and type comments. My PR only widens the gate but leaves the status === 429 check that still gets bypassed when a later target returns 403.

[hartmark]

Another PR already exists
#8559