Move the pending fallback, toast, and session-chain maps behind a shared controller initialized from the hook factory. This preserves the existing singleton semantics because exported helpers and hook instances still resolve the same lazily initialized controller while hook.ts stays under the 200-line limit.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
When users configure agents.sisyphus-junior.model, category sessions
should use that model without falling back to hardcoded
AGENT_MODEL_REQUIREMENTS. Two leaks existed:
1. Launch-time: category-resolver.ts did not check overrideModel when
deciding whether to use the hardcoded fallbackChain. Fixed by adding
overrideModel to the suppression condition.
2. Runtime retry: model-fallback hook.ts treated undefined fallbackChain
(from setSessionFallbackChain(id, undefined)) as 'no override' and
fell through to AGENT_MODEL_REQUIREMENTS on session.error/status
retry. Fixed by storing explicit empty array and checking .has()
instead of truthiness.
Tests added:
- hook.test.ts: explicit empty session fallback suppresses agent chain
- event.model-fallback-2941.test.ts: session.error does not arm retry
- category-resolver.test.ts: overrideModel suppresses fallbackChain
- tools.test.ts: sisyphusJuniorModel override assertion
- model-fallback hook: mock selectFallbackProvider and add _resetForTesting()
to test-setup.ts to clear module-level state between files
- fallback-retry-handler: add afterAll(mock.restore) and use mockReturnValueOnce
to prevent connected-providers mock leaking to subsequent test files
- opencode-config-dir: use win32.join for Windows APPDATA path construction
so tests pass on macOS (path.join uses POSIX semantics regardless of
process.platform override)
- system-loaded-version: use resolveSymlink from file-utils instead of
realpathSync to handle macOS /var -> /private/var symlink consistently
All 4456 tests pass (0 failures) on full bun test suite.
The getNextFallback function returned raw model names from the
hardcoded fallback chain without transforming them for the target
provider. For example, github-copilot requires dot notation
(claude-sonnet-4.6) but the fallback chain stores hyphen notation
(claude-sonnet-4-6).
The background-agent retry handler already calls
transformModelForProvider correctly, but the sync chat.message
hook in model-fallback was missing it — a copy-paste omission.
Add transformModelForProvider call in getNextFallback and a test
verifying github-copilot model name transformation.