refactor: remove goop-discuss and goop-quick commands, keep the discuss phase

[hffmnnj]

Stacked on #287.

Two slash commands go away. The discuss phase does not.

That distinction is the whole point of this change, so it is worth stating plainly: /goop-discuss and /goop-quick are deleted as commands, while discuss remains a fully legal phase in the state machine, the DB schema, and phase enforcement. Discovery is entered by describing what you want rather than by typing a command name.

Commands removed

commands/goop-discuss.md and commands/goop-quick.md are deleted, leaving exactly seven command files. Every inventory assertion was updated to match: EXPECTED_COMMAND_FILES 9 → 7, the slashcommand registry, and a resolver prompt-file count that the initial search missed and the suite caught.

Phase preserved

WORKFLOW_PHASES still reads ["idle", "discuss", "plan", "execute", "accept"]. VALID_TRANSITIONS still carries idle → discuss, discuss → plan | idle, and plan → discuss. The discuss enforcement block in phase-context.ts is untouched, and no migration rewrites the phase value.

semantic-invariants.test.ts asserts five phases and diffs empty against the branch base — it was never edited, because five was still the right answer.

Intent classifier

goop_infer_intent still recognizes discovery and small-fix intent. What changed is that those intents no longer map to commands that do not exist: both now map to "" in COMMAND_MAP, the same shape create-workflow, transition, and chat already used.

That exposed a rendering bug — a commandless intent with autoRun produced a line reading Running automatically``, empty backticks and all. formatResult now branches on whether a command string exists, so command-backed intents keep their existing output byte-for-byte and commandless ones read "Routing automatically (no command needed)".

Deciding what discovery auto-run should mean now that no command backs it is design work for a later change, not this one.

Reference sweep

Nineteen files carried prose telling users to run the removed commands: runtime hint strings in the status and setup tools, the idle guidance in phase-context.ts, five command docs, eight reference documents, and the planner agent.

Where a doc said "run /goop-discuss", it now describes stating your goal in prose. Where it said "run /goop-quick", the option is removed rather than replaced, since quick mode is being retired.

This also swept prose deferred from #287: the ### Validators section in references/enforcement-system.md documenting deleted functions, the Factory-pattern example in references/architecture-design.md, and the validation-contract gate references in the planner agent, renamed to "Requirements-Completeness Gate (MH15)" consistently across all three sites.

The self-edit carve-out in references/dispatch-patterns.md was removed rather than reworded. It described a quick-mode exception that was never code-enforced — orchestrator-enforcement.ts denies every recognized orchestrator implementation write with no such exception. That was confirmed against the hook, not assumed.

Verification

typecheck   clean
tests       2507 pass, 0 fail, 7898 expect() calls, 123 files
lint        7 errors, 17 warnings — byte-identical to main's pre-existing baseline
commands/   7 files

The suite goes 2509 → 2507. Both removed tests come from real-prompts.test.ts generating one it() per command file; 9 files became 7. No test file was added or removed, and no test body was deleted.

All five commits were checked out individually and run: b31d7de at 2509/0, the remaining four at 2507/0. The PR history contains no red commit.

The acceptance check for stale references returns zero hits across commands/, references/, and agents/, and zero non-comment hits in src/. The thirteen surviving matches are all comments — historical byte-delta entries in the prompt-audit log, and explanatory notes on the deliberate empty command mapping and its negative assertions.

Not in scope

The quick task mode still exists in TASK_MODES and mode detection. Only the command was removed here; the mode is retired later, when mode and depth are absorbed into the effort dial.