Removes five unused funcs/vars/fields that golangci-lint had been
flagging (anthropic.toolCallDoneEvent, mistral.translateMessages,
hook.newError, subprocess.vibeParser.lastAssistantMsgID, tui.cBase),
two ineffectual assignments (tui/rendering.go visible-window loop,
subprocess stream_test setup), and a stale if/HasPrefix that's now a
strings.TrimPrefix.
Wires errcheck onto every subprocess / stream lifecycle path so a
failed close or shutdown is at least logged rather than silently
dropped:
- engine/loop.go: stream.Close on both the error and success paths
- mcp/manager.go: Shutdown when StartAll partial-fails; Transport
close after Initialize failure
- mcp/transport.go: stdin.Close + syscall.Kill on graceful-timeout
fallback
- slm/download.go: Close propagated as a named-return error on the
success path; explicitly discarded on the rollback path
- slm/classifier.go, slm/manager.go, hook/prompt.go, context/summarize.go,
config/write.go, cmd/gnoma/main.go, tool/fs/grep.go: explicit
ignores or error logging on Close / Shutdown / WalkDir / Scanln
Production-code errcheck and ineffassign are now zero. Remaining
golangci-lint output is test-only Close-in-defer noise plus
stylistic staticcheck QF suggestions, left alone.