feat: add trip() to force breaker into open state

[abnegate]

Summary

Adds a single trip() method to CircuitBreaker that forces the breaker into the OPEN state, syncing through any configured cache adapter and recording state telemetry.

Why

• Tests that exercise breaker-open behaviour (e.g. fallback paths in consumers) currently have to drive N synthetic failures through call() to flip state. trip() is the obvious shortcut.
• Operationally, an admin endpoint that wants to disable a backend ("break the circuit on $namespace") needs a way to set OPEN without calling call().

Behaviour

• Idempotent: calling trip() on an already-open breaker refreshes openedAt without re-recording a transition.
• Cache-backed when an Adapter is configured (state, openedAt persisted).
• Records the breaker.transitions counter and updates state gauges as transitionToOpen() does internally.

Test plan

• Unit test: trips closed → open
• Unit test: idempotent on already-open
• Unit test: persists state through cache adapter
• Unit test: emits transition + state telemetry

[greptile-apps]

Greptile Summary

This PR adds a single trip() method to CircuitBreaker that forces the breaker into the OPEN state by delegating to the existing syncFromCache(), transitionToOpen(), and recordState() pipeline. The implementation is correct and idempotent — transitionToOpen()'s existing $from === $to guard in recordTransition() already prevents duplicate transition events on re-trips, cache writes are handled by the existing setters, and the five new tests cover the key paths (state change, call short-circuiting, idempotency, cache persistence, and telemetry).

Confidence Score: 5/5

Safe to merge; no logic or data-correctness bugs found in the implementation.

All findings are P2 (test coverage gaps). The production code correctly delegates to existing, well-tested internals with no new edge cases introduced.

tests/unit/CircuitBreakerTest.php — minor gaps in telemetry assertions for the two new test methods.

Important Files Changed

Filename	Overview
src/CircuitBreaker/CircuitBreaker.php	Adds trip() — a thin, correct public wrapper around the existing syncFromCache() + transitionToOpen() + recordState() pipeline; no logic bugs found.
tests/unit/CircuitBreakerTest.php	Adds five trip() tests covering the core scenarios, but the idempotency test doesn't assert on telemetry and the telemetry test omits assertions on the failures/successes gauges emitted by recordState().

_{Reviews (3): Last reviewed commit: "feat: add trip() to force breaker into o..." | Re-trigger Greptile}