feat: Conductor renders AskUserQuestion decisions as prose by default

In Conductor, native AskUserQuestion is disabled and the MCP variant is
flaky, so skills now render every decision as a plain-text prose brief the
user answers by typing a letter — proactively, not as a failure reaction.

- Preamble emits CONDUCTOR_SESSION, gated on != headless so eval/CI inside
  Conductor still BLOCKs instead of rendering prose to nobody.
- AskUserQuestion Format gains a Conductor-default-prose rule (auto-decide
  preferences still apply first; prose decisions log via gstack-question-log
  since PostToolUse never fires), a one-way/destructive typed-confirmation
  rule, and a typed-reply continuation protocol for split chains.
- Regenerated all SKILL.md + ship golden fixtures; bumped affected carve
  skeleton caps to absorb the always-loaded additions.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

scripts/resolvers/preamble/generate-ask-user-format.ts

@@ -7,7 +7,9 @@ export function generateAskUserFormat(_ctx: TemplateContext): string {
 
 "AskUserQuestion" can resolve to two tools at runtime: the **host MCP variant** (e.g. \`mcp__conductor__AskUserQuestion\` — appears in your tool list when the host registers it) or the **native** Claude Code tool.
 
-**Rule:** if any \`mcp__*__AskUserQuestion\` variant is in your tool list, prefer it. Hosts may disable native AUQ via \`--disallowedTools AskUserQuestion\` (Conductor does, by default) and route through their MCP variant; calling native there silently fails. Same questions/options shape; same decision-brief format applies.
+**Conductor rule (read before the MCP rule):** if \`CONDUCTOR_SESSION: true\` was echoed by the preamble, do NOT call AskUserQuestion at all — neither native nor any \`mcp__*__AskUserQuestion\` variant. Render EVERY decision brief as the **prose form** below and STOP. This is proactive, not a reaction to a failure: Conductor disables native AUQ and its MCP variant is flaky (it returns \`[Tool result missing due to internal error]\`), so prose is the reliable path. **Auto-decide preferences still apply first:** if a \`[plan-tune auto-decide] <id> → <option>\` result has already surfaced for a question, proceed with that option (no prose). Because in Conductor you go straight to prose without ever calling the tool, this auto-decide-first ordering is enforced HERE, not only by the PreToolUse hook. When you render a Conductor prose brief, also capture it with \`bin/gstack-question-log\` (the PostToolUse capture hook never fires on a prose path, so \`/plan-tune\` history/learning depends on this call).
+
+**Rule (non-Conductor):** if any \`mcp__*__AskUserQuestion\` variant is in your tool list, prefer it. Hosts may disable native AUQ via \`--disallowedTools AskUserQuestion\` (Conductor does, by default) and route through their MCP variant; calling native there silently fails. Same questions/options shape; same decision-brief format applies.
 
 If AskUserQuestion is unavailable (no variant in your tool list) OR a call to it fails, do NOT silently auto-decide or write the decision to the plan file as a substitute. Follow the **failure fallback** below.
 
@@ -29,7 +31,11 @@ Tell three outcomes apart:
 2. **Completeness scores per choice** — explicit \`Completeness: X/10\` on EACH choice (10 complete, 7 happy-path, 3 shortcut); use the kind-note when options differ in kind not coverage, but never silently drop the score.
 3. **The recommendation and why** — a \`Recommendation: <choice> because <reason>\` line plus the \`(recommended)\` marker on that choice.
 
-Layout: a \`D<N>\` title + a one-line note that AskUserQuestion failed and to reply with a letter; the issue ELI10; the Recommendation line; then ONE paragraph per choice carrying its \`(recommended)\` marker, its \`Completeness: X/10\`, and 2-4 sentences of reasoning — never a bare bullet list; a closing \`Net:\` line. Split chains / 5+ options: one prose block per per-option call, in sequence. Then STOP and wait — the user's typed answer is the decision. In plan mode this satisfies end-of-turn like a tool call.
+Layout: a \`D<N>\` title + a one-line note to reply with a letter (in Conductor this is the normal path; elsewhere it means AskUserQuestion was unavailable or errored); the issue ELI10; the Recommendation line; then ONE paragraph per choice carrying its \`(recommended)\` marker, its \`Completeness: X/10\`, and 2-4 sentences of reasoning — never a bare bullet list; a closing \`Net:\` line. Split chains / 5+ options: one prose block per per-option call, in sequence. Then STOP and wait — the user's typed answer is the decision. In plan mode this satisfies end-of-turn like a tool call.
+
+**Continuation — mapping a typed reply back to a brief.** Each brief carries a stable label (\`D<N>\`, or \`D<N>.k\` in a split chain). The user references it (e.g. "3.2: B"). A bare letter maps to the single most-recent UNANSWERED brief; if more than one is open (a split chain), do NOT guess — ask which \`D<N>.k\` it answers. Never apply a bare letter ambiguously across a chain.
+
+**One-way / destructive confirmations in prose.** When the decision is a one-way door (irreversible or destructive — delete, force-push, drop, overwrite), prose is a WEAKER gate than the tool, so make it stronger: require an explicit typed confirmation (the exact option letter or word), state plainly what is irreversible, and NEVER proceed on a vague, partial, or ambiguous reply — re-ask instead. Treat silence or "ok"/"sure" without the explicit choice as not-yet-confirmed.
 
 ### Format
 
@@ -113,7 +119,7 @@ Before calling AskUserQuestion, verify:
 - [ ] (recommended) label on one option (even for neutral-posture)
 - [ ] Dual-scale effort labels on effort-bearing options (human / CC)
 - [ ] Net line closes the decision
-- [ ] You are calling the tool, not writing prose — unless the documented failure fallback applies (then: prose with the mandatory triad — issue ELI10, per-choice Completeness, Recommendation + \`(recommended)\` — and a "reply with a letter" instruction, then STOP)
+- [ ] You are calling the tool, not writing prose — unless \`CONDUCTOR_SESSION: true\` (then prose is the DEFAULT, not the tool) OR the documented failure fallback applies (then: prose with the mandatory triad — issue ELI10, per-choice Completeness, Recommendation + \`(recommended)\` — and a "reply with a letter" instruction, then STOP)
 - [ ] Non-ASCII characters (CJK / accents) written directly, NOT \\u-escaped
 - [ ] If you had 5+ options, you split (or batched into ≤4-groups) — did NOT drop any
 - [ ] If you split, you checked dependencies between options before firing the chain

scripts/resolvers/preamble/generate-preamble-bash.ts

@@ -36,6 +36,13 @@ echo "REPO_MODE: $REPO_MODE"
 _SESSION_KIND=$(${ctx.paths.binDir}/gstack-session-kind 2>/dev/null || echo "interactive")
 case "$_SESSION_KIND" in spawned|headless|interactive) ;; *) _SESSION_KIND="interactive" ;; esac
 echo "SESSION_KIND: $_SESSION_KIND"
+# Conductor host: AskUserQuestion is unreliable here (native disabled, MCP
+# variant flaky), so skills render decisions as prose instead of calling the
+# tool. Gated on !headless so an eval/CI run INSIDE Conductor (GSTACK_HEADLESS)
+# still BLOCKs rather than rendering prose to nobody.
+if [ "$_SESSION_KIND" != "headless" ] && { [ -n "\${CONDUCTOR_WORKSPACE_PATH:-}" ] || [ -n "\${CONDUCTOR_PORT:-}" ]; }; then
+  echo "CONDUCTOR_SESSION: true"
+fi
 _LAKE_SEEN=$([ -f ~/.gstack/.completeness-intro-seen ] && echo "yes" || echo "no")
 echo "LAKE_INTRO: $_LAKE_SEEN"
 _TEL=$(${ctx.paths.binDir}/gstack-config get telemetry 2>/dev/null || true)