Brings the project to a clean `make lint` baseline (0 issues).
Mechanical:
- Wrap deferred resp.Body.Close() in closures (router/discovery.go,
router/probe.go) so the unchecked return surfaces as `_ = ...`.
- Apply `_ = ...` (single or multi-return blank) to test-file calls
that intentionally ignore errors: os.MkdirAll / os.WriteFile / os.Chdir
in setup paths, Close / Shutdown in teardown, Submit / Spawn / Send /
LoadDir in tests that assert on side effects.
Structural:
- engine.handleRequestTooLarge drops the unused req parameter and
rebuilds the request from compacted history (SA4009 — argument was
overwritten before first use).
- provider.ClassifyHTTPStatus and google.applyCapabilityOverrides switch
to tagged switches over the discriminator (QF1002).
- tui.app.go MouseWheel + inputMode and cmd/gnoma main slm-status use
tagged switches in place of equality chains (QF1003).
- cmd/gnoma main.go merges a var decl with its immediate assignment
(S1021).
- Three empty-branch sites (dispatcher_test, loader_test,
coordinator_test) become real assertions or get the dead `if` removed
(SA9003).
Stop retrying llama.cpp 500s that are deterministic tool-parse failures
by inspecting the error message body (ClassifyHTTPError). Wrap OpenAI SDK
errors as ProviderError so the engine's retry logic classifies them. Add
localInitPrompt for local models that uses sequential fs_* calls instead
of spawn_elfs (which local models can't produce reliably).