merge: integrate origin/main (v1.1.0.0) — V1 + Puppeteer parity + /plan-tune

Big merge. Main shipped three releases while this branch was in flight:
- v0.19.0.0 /plan-tune skill (observational layer; dual-track dev profile)
- v1.0.0.0 V1 prompts (simpler, outcome-framed, jargon-glossed) + LOC receipts
- v1.1.0.0 browse Puppeteer parity (load-html, file://, --selector, --scale)

This branch bumps to v1.2.0.0 (above main's v1.1.0.0) per the
branch-scoped-version rule in CLAUDE.md. My "0.19.0.0" CHANGELOG entry
is renamed to "1.2.0.0" and dated 2026-04-18 to land above main's trail.

Conflicts resolved:
- VERSION / package.json: 1.2.0.0
- CHANGELOG.md: preserved my entry at top (renamed), kept main's 1.1.0.0
  / 1.0.0.0 / 0.19.0.0 / 0.18.4.0 trail below in correct order
- .github/docker/Dockerfile.ci: kept my xz-utils + nodejs.org tarball
  fix (real CI bug fix main didn't have); absorbed main's retry loop
  structure for both apt and the tarball curl
- bin/gstack-config: kept both my checkpoint_mode/push section and
  main's explain_level writing-style section
- scripts/resolvers/preamble.ts: kept my submodule refactor as the
  file shape; extracted main's new generateWritingStyle and
  generateWritingStyleMigration into scripts/resolvers/preamble/
  submodules; absorbed main's generateQuestionTuning import
- All generated SKILL.md files: resolved by regen via
  bun run gen:skill-docs --host all (per CLAUDE.md: never hand-merge
  generated files — resolve templates and regen)
- Ship golden fixtures (claude/codex/factory): refreshed

Tier 2 preamble composition now includes all 8 sections: context
recovery, ask-user-format, writing-style, completeness, confusion,
continuous checkpoint, context health, question tuning.

Main also brought new test files from /plan-tune: skill-e2e-plan-tune,
upgrade-migration-v1, v0-dormancy, writing-style-resolver. All absorbed.
468 tests pass.

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

scripts/resolvers/preamble.ts

@@ -15,8 +15,10 @@
  *   2. If _TEL != "off" AND binary exists: gstack-telemetry-log for remote reporting
  */
 
+
 import type { TemplateContext } from './types';
 import { generateModelOverlay } from './model-overlay';
+import { generateQuestionTuning } from './question-tuning';
 
 // Core bootstrap
 import { generatePreambleBash } from './preamble/generate-preamble-bash';
@@ -30,6 +32,7 @@ import { generateProactivePrompt } from './preamble/generate-proactive-prompt';
 import { generateRoutingInjection } from './preamble/generate-routing-injection';
 import { generateVendoringDeprecation } from './preamble/generate-vendoring-deprecation';
 import { generateSpawnedSessionCheck } from './preamble/generate-spawned-session-check';
+import { generateWritingStyleMigration } from './preamble/generate-writing-style-migration';
 
 // Host-specific instructions
 import { generateBrainHealthInstruction } from './preamble/generate-brain-health-instruction';
@@ -40,6 +43,7 @@ import { generateVoiceDirective } from './preamble/generate-voice-directive';
 // Tier 2+ context and interaction framework
 import { generateContextRecovery } from './preamble/generate-context-recovery';
 import { generateAskUserFormat } from './preamble/generate-ask-user-format';
+import { generateWritingStyle } from './preamble/generate-writing-style';
 import { generateCompletenessSection } from './preamble/generate-completeness-section';
 import { generateConfusionProtocol } from './preamble/generate-confusion-protocol';
 import { generateContinuousCheckpoint } from './preamble/generate-continuous-checkpoint';
@@ -72,6 +76,7 @@ export function generatePreamble(ctx: TemplateContext): string {
   const sections = [
     generatePreambleBash(ctx),
     generateUpgradeCheck(ctx),
+    generateWritingStyleMigration(ctx),
     generateLakeIntro(),
     generateTelemetryPrompt(ctx),
     generateProactivePrompt(ctx),
@@ -84,10 +89,12 @@ export function generatePreamble(ctx: TemplateContext): string {
     ...(tier >= 2 ? [
       generateContextRecovery(ctx),
       generateAskUserFormat(ctx),
+      generateWritingStyle(ctx),
       generateCompletenessSection(),
       generateConfusionProtocol(),
       generateContinuousCheckpoint(),
       generateContextHealth(),
+      generateQuestionTuning(ctx),
     ] : []),
     ...(tier >= 3 ? [generateRepoModeSection(), generateSearchBeforeBuildingSection(ctx)] : []),
     generateCompletionStatus(ctx),