merge: integrate origin/main (v0.18.1.0) into open-agents-learnings

Main moved forward 6 commits while this branch was local. Integrated
both sides preserving all functionality:

From main (v0.16.4.0 → v0.18.1.0):
- v0.17.0.0 — UX behavioral foundations + ux-audit (generateUXPrinciples,
  {{UX_PRINCIPLES}} placeholder, triggers frontmatter on skills)
- v0.18.0.0 — Confusion Protocol, Hermes + GBrain hosts, brain-first
  resolver (generateBrainHealthInstruction, generateConfusionProtocol,
  generateGBrainContextLoad, generateGBrainSaveResults, hosts/gbrain.ts,
  hosts/hermes.ts, scripts/resolvers/gbrain.ts, GBrain bash health check)
- v0.18.0.1 — ngrok Windows build fix
- 0cc830b6 — tilde-in-assignment permission fix
- cc42f14a — gstack compact design doc (tabled)
- 822e843a — headed browser auto-shutdown + disconnect cleanup (v0.18.1.0)

Integration approach: keep this branch's preamble.ts submodule refactor
as the structure of record. Extracted main's two new generators into
their own submodules:
- scripts/resolvers/preamble/generate-brain-health-instruction.ts
- scripts/resolvers/preamble/generate-confusion-protocol.ts

Updated scripts/resolvers/preamble/generate-preamble-bash.ts to absorb
main's GBrain health check (host-conditional on gbrain/hermes).

scripts/resolvers/index.ts now imports BOTH:
- This branch's adds: MODEL_OVERLAY, TASTE_PROFILE, BIN_DIR resolvers
- Main's adds: UX_PRINCIPLES, GBRAIN_CONTEXT_LOAD, GBRAIN_SAVE_RESULTS
  resolvers

scripts/resolvers/design.ts keeps both generateTasteProfile (this
branch) and generateUXPrinciples (main). Sibling exports, no overlap.

scripts/gen-skill-docs.ts keeps both this branch's --model flag wiring
and main's edits.

Templates auto-merged where possible. The 35 generated SKILL.md /
golden conflicts auto-resolved via `bun run gen:skill-docs --host all`
followed by re-snapshotting the ship goldens for claude/codex/factory.

Verification:
- bun run gen:skill-docs --host all completes cleanly
- bun test: 1 pre-existing failure (gstack-community-dashboard Supabase
  network test, 235s timeout). NOT related to merge — unchanged Supabase
  test infra times out without live network. Flagged in PR body.

Token-ceiling warnings on plan-ceo-review (29K), office-hours (26K),
and ship (34K). These existed on origin/main before the merge — the
preamble grew substantially from main's GBrain + UX additions plus this
branch's continuous-checkpoint, context-health, model-overlay, taste-profile,
and feature-discovery additions. Worth a follow-up reduction pass but
doesn't block this merge.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/resolvers/preamble.ts

@@ -31,6 +31,9 @@ import { generateRoutingInjection } from './preamble/generate-routing-injection'
 import { generateVendoringDeprecation } from './preamble/generate-vendoring-deprecation';
 import { generateSpawnedSessionCheck } from './preamble/generate-spawned-session-check';
 
+// Host-specific instructions
+import { generateBrainHealthInstruction } from './preamble/generate-brain-health-instruction';
+
 // Behavioral / voice
 import { generateVoiceDirective } from './preamble/generate-voice-directive';
 
@@ -38,6 +41,7 @@ import { generateVoiceDirective } from './preamble/generate-voice-directive';
 import { generateContextRecovery } from './preamble/generate-context-recovery';
 import { generateAskUserFormat } from './preamble/generate-ask-user-format';
 import { generateCompletenessSection } from './preamble/generate-completeness-section';
+import { generateConfusionProtocol } from './preamble/generate-confusion-protocol';
 import { generateContinuousCheckpoint } from './preamble/generate-continuous-checkpoint';
 import { generateContextHealth } from './preamble/generate-context-health';
 
@@ -51,7 +55,7 @@ export { generateTestFailureTriage } from './preamble/generate-test-failure-tria
 // Preamble Composition (tier → sections)
 // ─────────────────────────────────────────────
 // T1: core + upgrade + lake + telemetry + voice(trimmed) + completion
-// T2: T1 + voice(full) + ask + completeness + context-recovery
+// T2: T1 + voice(full) + ask + completeness + context-recovery + confusion + checkpoint + context-health
 // T3: T2 + repo-mode + search
 // T4: (same as T3 — TEST_FAILURE_TRIAGE is a separate {{}} placeholder, not preamble)
 //
@@ -74,9 +78,17 @@ export function generatePreamble(ctx: TemplateContext): string {
     generateRoutingInjection(ctx),
     generateVendoringDeprecation(ctx),
     generateSpawnedSessionCheck(),
+    generateBrainHealthInstruction(ctx),
     generateModelOverlay(ctx),
     generateVoiceDirective(tier),
-    ...(tier >= 2 ? [generateContextRecovery(ctx), generateAskUserFormat(ctx), generateCompletenessSection(), generateContinuousCheckpoint(), generateContextHealth()] : []),
+    ...(tier >= 2 ? [
+      generateContextRecovery(ctx),
+      generateAskUserFormat(ctx),
+      generateCompletenessSection(),
+      generateConfusionProtocol(),
+      generateContinuousCheckpoint(),
+      generateContextHealth(),
+    ] : []),
     ...(tier >= 3 ? [generateRepoModeSection(), generateSearchBeforeBuildingSection(ctx)] : []),
     generateCompletionStatus(ctx),
   ];