fix(investigation): the symptom interview never ran for work shaped in discovery

[leeovery]

The defect

Step 3 asks whether the Symptoms section is already populated, treating that as "a previous session gathered these — don't re-interview".

But Step 1 populates Symptoms itself, from the discovery carrier and the seed, precisely so the user isn't asked to repeat what they already said. So every path into Step 3 arrives with the section populated:

Path	Symptoms at Step 3
fresh (no file)	populated by Step 1 from the carrier
restart	file deleted, Step 1 rebuilds and populates again
continue	earlier session's content stands

The guard is true in all three, so the interview is skipped in all three. For a bugfix shaped in discovery — which is how bugfixes reach investigation — symptom gathering never runs. It only works when there was no carrier and the section was left as template placeholders.

The fix

The guard was asking about the file when the question is about the session.

Step 0 already knows which it is: no file means fresh; a continue returns for Step 2 with the earlier session's symptoms standing; a restart deletes the file and returns for Step 1 to rebuild it. That distinction is now held as resumed, and Step 3 branches on it.

An engine fact couldn't serve here. After Step 1 the topic status is in-progress on both paths, so manifest get can't discriminate. Which arm Step 0 took is the only thing that can.

Scope — checked, not assumed

Contained to this skill. Discussion and research load the same shared resume reference, but their equivalent steps are unconditional guidance loads rather than an interview, so they have nothing to distinguish.

The other four "already populated" guards are sound. discovery_map non-empty, a key in items, review_cycle set — all engine state, none of it writable by the step immediately before. Only this one keyed on content.

Nothing downstream reads it. Symptoms appears only at this guard and in initialisation.

Also

Step 0's file-exists arm gains the routing footer it lacked. resume-detection.md routes every exit itself, which is exactly the shape that takes → On return, proceed as the reference directed. (#570) — its second instance, found incidentally.

Test plan and its limit

• Conventions lint 29/29; prose gate 19/19
• investigation-initialises-the-phase re-run to confirm the fresh arm and new footer walk cleanly

Not proven by test: the case stops before Step 3, so the resumed arm is unexercised. Catching this defect requires a case that starts with an existing investigation file and takes the continue path — a different fixture, and the one that would actually fail on the old prose. Worth adding; not in this PR.

🤖 Generated with Claude Code

Stack

1. docs(design): prose-tests programme design log #544
2. feat(prose-tests): the framework — cases, worlds, runner, skill #545
3. test(prose): feature happy-path corpus — five worlds, seven cases #546
4. test(prose): bugfix corpus — the investigation-centric surfaces #548
5. test: retry recursive teardown removals — kill a class of phantom failures #549
6. fix(entry-skills): close the handoff fences — six files render their arms wrong #550
7. docs: a contributing page for working on the system #551
8. fix(entry-skills): every handoff arm says to invoke the skill #552
9. fix(implementation): environment setup belongs to the setup reference alone #553
10. fix(prose-tests): the asserter is told which substitutions were armed #554
11. feat(prose-tests): the mid-flow substitution, and a world only prose can describe #555
12. test(prose): claims assert consequences, not what was displayed #556
13. feat(prose-tests): record everything the agents do, results included #557
14. fix(discussion-entry): the handoff reports the source it actually had #558
15. fix(prose-tests): the stop hook records, and names the model that walked #559
16. fix(prose-tests): command output was never actually recorded #560
17. feat(prose-tests): judge the walk as told, not the summary returned #561
18. feat(prose-tests): decide in code what an agent should not be deciding #562
19. test(prose): a case starts where a session starts #563
20. feat(prose-tests): walk on Sonnet, judge on Opus, escalate a failure #564
21. test(prose): give the eight read-only cases something that can fail #565
22. test(prose): only walks that can be observed, and checks that survive the trip #566
23. fix(prose-tests): the verdict names only the model the record names #567
24. test(prose): discovery, walked to the point where work first exists #568
25. fix(prose-tests): the asserter judges which of prose or walker was at fault #569
26. docs(conventions): a step whose reference routes every exit still signposts #570
27. test(prose): discovery's epic arm, to the same durability boundary #571
28. fix(prose-tests): keep the walk's closing turn, and name the one live difference #572
29. fix(prose-tests): prescribe the cross-check, drop a check that cannot fire, lint the scope #573
30. test(prose): declare the prose each case actually walks #574
31. fix(investigation): the symptom interview never ran for work shaped in discovery #575 👈 current
32. feat(prose-tests): conduct — playing a person where a script cannot reach #576
33. fix(prose-tests): what a write put in a file is evidence, not incident #577
34. fix(investigation): the interview starts from the carrier, not over it #578
35. test(prose): quick-fix scoping, the whole definition stage in one walk #579
36. fix(prose-tests): the world log is the walker's record #580
37. fix(prose-tests): a confirmed failure reports both runs' checks #581
38. fix(prose-tests): each prescribed command runs as written #582
39. fix(scoping): context gathering reads the whole carrier, asks only the gaps #583