Classify scheduler, orchestration, IPC read, and automation catch
blocks via logAppError + classifyUnknownError so each failure surfaces
a stable `module.subdomain.condition` code plus a kind. No behaviour
change — returns, throws, and fall-through are preserved; only log
prefixes and the taxonomy metadata are new.
Wave 1 coverage (26 sites, all non-database):
- orchestration/scheduler-lock-recovery (3)
- orchestration/scheduler-housekeeping (5)
- orchestration/scheduler-idle-automation (2)
- orchestration/scheduler-heartbeat (4)
- orchestration/turn-context (2)
- ipc-core-read-handlers (6)
- automation/automation-handlers (4)
Relax the Logger interface so `error` is optional, letting callers
whose deps expose only `{info, warn}` (scheduler contexts) pass in
directly without wrapping. The helper falls back to warn when error
is absent.
Establishes `src/main/errors/` with:
- `AppError` base + `Recoverable|UserInput|Upstream|Fatal` subclasses
keyed on a narrow `ErrorKind = "recoverable" | "user_input" |
"upstream" | "fatal"` union. Four kinds is deliberate: adding a fifth
is a conscious proposal, not an inline decision at a catch site.
- `classifyUnknownError(e, fallback)` — required-fallback-meta wrapper
that refuses to invent classification. If `e` is already an
AppError it is returned untouched; otherwise the call site's
intent wins and the raw value is preserved via `cause` (for Error
instances) or `context.raw` (for anything else).
- `logAppError(logger, raw, fallback, level?)` helper emits one
structured log line and returns the classified AppError so the
caller can still branch on `err.kind`.
Why this module exists: 248 catch blocks in src/main/ today are
overwhelmingly `} catch {}` or `log.warn(); return default`. Behaviour
is correct case-by-case but the codebase has no machine-readable signal
for "is this recoverable vs fatal", making it impossible to write
graceful-shutdown logic, telemetry buckets, or catch-site audits.
Part 2 migrates the top-20 high-frequency catch sites. Part 3 (tracked
as C6.2 proposal) covers the remaining 228.
No behavioural change in this commit — it only adds the classifier and
exports.
ZacharyZhang-NY