merge: origin/main into garrytan/multi-checkpoint-resume

Catches up 7 commits from main:
- c6e6a21d refactor: AI slop reduction with cross-model quality review (v0.16.3.0)
- 7e96fe29 fix: security wave 3 — 12 fixes, 7 contributors (v0.16.4.0)
- 23000672 feat: UX behavioral foundations + ux-audit command (v0.17.0.0)
- b805aa01 feat: Confusion Protocol, Hermes + GBrain hosts, brain-first resolver (v0.18.0.0)
- 6a785c57 fix: ngrok Windows build + close CI error-swallowing gap (v0.18.0.1)
- 0cc830b6 fix: avoid tilde-in-assignment to silence Claude Code permission prompts
- cc42f14a docs: gstack compact design doc (tabled pending Anthropic API)

Conflict resolution:
- ship/SKILL.md.tmpl line 402: HEAD had "## Step 12: Version bump" from
  the renumber refactor; origin/main added {{GBRAIN_SAVE_RESULTS}} above
  "## Step 4: Version bump". Resolved by keeping origin/main's new
  placeholder AND my branch's "Step 12" heading.
- ship/SKILL.md: regenerated from resolved template (per CLAUDE.md
  policy: never resolve generated files manually).

All skill docs regenerated for all 9 hosts (claude, kiro, opencode,
slate, cursor, openclaw, factory, hermes, gbrain) to reflect the
merged template.

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

CLAUDE.md

@@ -20,6 +20,8 @@ bun run dev:skill    # watch mode: auto-regen + validate on change
 bun run eval:list    # list all eval runs from ~/.gstack-dev/evals/
 bun run eval:compare # compare two eval runs (auto-picks most recent)
 bun run eval:summary # aggregate stats across all eval runs
+bun run slop          # full slop-scan report (all files)
+bun run slop:diff     # slop findings in files changed on this branch only
 ```
 
 `test:evals` requires `ANTHROPIC_API_KEY`. Codex E2E tests (`test/codex-e2e.test.ts`)
@@ -66,14 +68,15 @@ gstack/
 ├── hosts/           # Typed host configs (one per AI agent)
 │   ├── claude.ts    # Primary host config
 │   ├── codex.ts, factory.ts, kiro.ts  # Existing hosts
-│   ├── opencode.ts, slate.ts, cursor.ts, openclaw.ts  # New hosts
+│   ├── opencode.ts, slate.ts, cursor.ts, openclaw.ts  # IDE hosts
+│   ├── hermes.ts, gbrain.ts  # Agent runtime hosts
 │   └── index.ts     # Registry: exports all, derives Host type
 ├── scripts/         # Build + DX tooling
 │   ├── gen-skill-docs.ts  # Template → SKILL.md generator (config-driven)
 │   ├── host-config.ts     # HostConfig interface + validator
 │   ├── host-config-export.ts  # Shell bridge for setup script
 │   ├── host-adapters/     # Host-specific adapters (OpenClaw tool mapping)
-│   ├── resolvers/   # Template resolver modules (preamble, design, review, etc.)
+│   ├── resolvers/   # Template resolver modules (preamble, design, review, gbrain, etc.)
 │   ├── skill-check.ts     # Health dashboard
 │   └── dev-skill.ts       # Watch mode
 ├── test/            # Skill validation + eval tests
@@ -136,6 +139,11 @@ SKILL.md files are **generated** from `.tmpl` templates. To update docs:
 To add a new browse command: add it to `browse/src/commands.ts` and rebuild.
 To add a snapshot flag: add it to `SNAPSHOT_FLAGS` in `browse/src/snapshot.ts` and rebuild.
 
+**Token ceiling:** Generated SKILL.md files must stay under 100KB (~25K tokens).
+`gen-skill-docs` warns if any file exceeds this. If a skill template grows past the
+ceiling, consider extracting optional sections into separate resolvers that only
+inject when relevant, or making verbose evaluation rubrics more concise.
+
 **Merge conflicts on SKILL.md files:** NEVER resolve conflicts on generated SKILL.md
 files by accepting either side. Instead: (1) resolve conflicts on the `.tmpl` templates
 and `scripts/gen-skill-docs.ts` (the sources of truth), (2) run `bun run gen:skill-docs`
@@ -250,6 +258,62 @@ Examples of good bisection:
 When the user says "bisect commit" or "bisect and push," split staged/unstaged
 changes into logical commits and push.
 
+## Slop-scan: AI code quality, not AI code hiding
+
+We use [slop-scan](https://github.com/benvinegar/slop-scan) to catch patterns where
+AI-generated code is genuinely worse than what a human would write. We are NOT trying
+to pass as human code. We are AI-coded and proud of it. The goal is code quality.
+
+```bash
+npx slop-scan scan .          # human-readable report
+npx slop-scan scan . --json   # machine-readable for diffing
+```
+
+Config: `slop-scan.config.json` at repo root (currently excludes `**/vendor/**`).
+
+### What to fix (genuine quality improvements)
+
+- **Empty catches around file ops** — use `safeUnlink()` (ignores ENOENT, rethrows
+  EPERM/EIO). A swallowed EPERM in cleanup means silent data loss.
+- **Empty catches around process kills** — use `safeKill()` (ignores ESRCH, rethrows
+  EPERM). A swallowed EPERM means you think you killed something you didn't.
+- **Redundant `return await`** — remove when there's no enclosing try block. Saves a
+  microtask, signals intent.
+- **Typed exception catches** — `catch (err) { if (!(err instanceof TypeError)) throw err }`
+  is genuinely better than `catch {}` when the try block does URL parsing or DOM work.
+  You know what error you expect, so say so.
+
+### What NOT to fix (linter gaming, not quality)
+
+- **String-matching on error messages** — `err.message.includes('closed')` is brittle.
+  Playwright/Chrome can change wording anytime. If a fire-and-forget operation can fail
+  for ANY reason and you don't care, `catch {}` is the correct pattern.
+- **Adding comments to exempt pass-through wrappers** — "alias for active session" above
+  a method just to trip slop-scan's exemption rule is noise, not documentation.
+- **Converting extension catch-and-log to selective rethrow** — Chrome extensions crash
+  entirely on uncaught errors. If the catch logs and continues, that IS the right pattern
+  for extension code. Don't make it throw.
+- **Tightening best-effort cleanup paths** — shutdown, emergency cleanup, and disconnect
+  code should use `safeUnlinkQuiet()` (swallows ALL errors). A cleanup path that throws
+  on EPERM means the rest of cleanup doesn't run. That's worse.
+
+### Utilities in `browse/src/error-handling.ts`
+
+| Function | Use when | Behavior |
+|----------|----------|----------|
+| `safeUnlink(path)` | Normal file deletion | Ignores ENOENT, rethrows others |
+| `safeUnlinkQuiet(path)` | Shutdown/emergency cleanup | Swallows all errors |
+| `safeKill(pid, signal)` | Sending signals | Ignores ESRCH, rethrows others |
+| `isProcessAlive(pid)` | Boolean process checks | Returns true/false, never throws |
+
+### Score tracking
+
+Baseline (2026-04-09, before cleanup): 100 findings, 432.8 score, 2.38 score/file.
+After cleanup: 90 findings, 358.1 score, 1.96 score/file.
+
+Don't chase the number. Fix patterns that represent actual code quality problems.
+Accept findings where the "sloppy" pattern is the correct engineering choice.
+
 ## Community PR guardrails
 
 When reviewing or merging community PRs, **always AskUserQuestion** before accepting