Phase 2: THAC0 core OutputManager

[djdarcy]

Phase 2 of #65. Implement OutputManager with THAC0 emit logic (level <= threshold), per-channel overrides via ChannelConfig, error() as emit(-3), hint() delegates level to emit(), singleton + init_output, output.py backward-compat shim.

[djdarcy]

Phase 2 — Complete

What was done

Implemented the THAC0 core in utils/log_lib/manager.py:

OutputManager — Central coordinator with:

• emit(level, message, *, channel='general', **kwargs) — Verbosity-gated output. Threshold is per-channel override or global verbosity. At -4 (hard wall), nothing emits.
• hint(hint_id, context, **kwargs) — Two filters: context filter (orthogonal to THAC0) + level filter (delegated to threshold check). Deduplication tracked per session.
• error(message) — Implemented as emit(-3, ..., channel='error'). Shows at any verbosity >= -3.
• progress(count, elapsed) — emit(1, ..., channel='progress').
• channel_active(channel) — Gating check for callers to avoid expensive operations. Returns True if level-0 message on that channel would be shown.
• quiet property — Backward compat: True when verbosity < 0.

Singleton management:

• init_output(verbosity, quiet, channels) — Parses channel specs, applies opt-in defaults, creates singleton.
• get_output() — Returns singleton, creating default if needed.

Key design decisions

1. error() as emit(-3): Errors are just low-level emit calls. They show at any verbosity >= -3, silenced only at hard wall (-4). This means per-channel overrides can theoretically silence errors on specific channels — powerful but the user controls it.

2. hint() two-filter model: Context filtering ('error', 'result', 'verbose') is orthogonal to THAC0 level. Context is about when the hint is relevant. Level is about how loud. Both filters apply independently.

3. Opt-in channels: vals and trace get default override of -1 (off). Explicit --show vals or --show trace activates them. Other channels follow global verbosity.

4. quiet=True backward compat: OutputManager(quiet=True) and init_output(quiet=True) convert to verbosity=-1 internally.

Verification

11 checks passed on first run:

• THAC0 emit at different levels
• Per-channel override
• Hard wall (-4)
• error() as emit(-3)
• channel_active() gating
• parse_channel_spec()
• format_channel_list()
• init_output with channels
• Backward compat quiet=True

All 29 existing test_output.py tests pass after 2 fixes:

• Added quiet: bool = False param to OutputManager.init()
• Updated singleton test to reference utils.log_lib.manager._manager

Analysis

See 2026-02-13__18-48-22__dev-workflow_issue65-implementation-plan.md for full design rationale.