fix(host-paths): use $HOME instead of ~ in non-env-var host paths

`HOST_PATHS` for Claude (and any future host with `usesEnvVars=false`) was
built from `~/${config.globalRoot}`. The resulting binDir is then
interpolated into double-quoted bash strings by several preamble emitters,
e.g. `generate-brain-sync-block.ts:45`:

  _BRAIN_SYNC_BIN="${ctx.paths.binDir}/gstack-brain-sync"

POSIX shells do NOT expand `~` inside double quotes. The emitted line
becomes a literal `"~/.claude/.../gstack-brain-sync"`, which fails with
`exit 127, No such file or directory` when invoked. Both stderr and the
exit code are suppressed by `2>/dev/null || true`, so the failure is
silent: skill preambles call `gstack-brain-sync --once` on every skill
boundary, but it never runs. The artifacts queue (~/.gstack/.brain-queue.jsonl)
grows indefinitely while last-push stays at "never". Codex/Factory hosts
are unaffected because they use `$GSTACK_BIN`, which DOES expand inside
double quotes.

Fix: emit `$HOME/${config.globalRoot}` instead. Identical semantics outside
quotes, correct semantics inside quotes.

Why CI didn't catch it:
- `test/host-config.test.ts:246` asserted the broken form as the
  expected value (`expect(...).toBe('~/.claude/skills/gstack/bin')`).
- The Claude golden fixture (`test/fixtures/golden/claude-ship-SKILL.md`)
  was generated from the broken code path, so the regression suite was
  comparing the bug against itself.

Changes:
- `scripts/resolvers/types.ts`: emit `$HOME/...` for non-env-var hosts
  (one-line change + WHY comment).
- `test/host-config.test.ts`: update existing assertions to expect
  `$HOME/...`. Add a narrow regression guard that asserts no non-env-var
  host's binDir/skillRoot/browseDir/designDir/makePdfDir begins with `~`
  (i.e., is safe to interpolate inside double quotes).
- Regenerated artifacts via `bun run gen:skill-docs --host all`:
  42 Claude-host SKILL.md files + the claude-ship golden fixture flip
  from `~/...` to `$HOME/...`. Codex/Factory artifacts unchanged.

Test plan:
- `bun test test/host-config.test.ts` — 74 pass, 0 fail (includes new guard).
- `bun test test/gen-skill-docs.test.ts test/brain-sync.test.ts` —
  412 pass, 0 fail.
- `bun run test` (main suite, e2e excluded) — green.

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

Author: jisulee42

SKILL.md

@@ -24,66 +24,66 @@ triggers:
 ## Preamble (run first)
 
 ```bash
-_UPD=$(~/.claude/skills/gstack/bin/gstack-update-check 2>/dev/null || .claude/skills/gstack/bin/gstack-update-check 2>/dev/null || true)
+_UPD=$($HOME/.claude/skills/gstack/bin/gstack-update-check 2>/dev/null || .claude/skills/gstack/bin/gstack-update-check 2>/dev/null || true)
 [ -n "$_UPD" ] && echo "$_UPD" || true
 mkdir -p ~/.gstack/sessions
 touch ~/.gstack/sessions/"$PPID"
 _SESSIONS=$(find ~/.gstack/sessions -mmin -120 -type f 2>/dev/null | wc -l | tr -d ' ')
 find ~/.gstack/sessions -mmin +120 -type f -exec rm {} + 2>/dev/null || true
-_PROACTIVE=$(~/.claude/skills/gstack/bin/gstack-config get proactive 2>/dev/null || echo "true")
+_PROACTIVE=$($HOME/.claude/skills/gstack/bin/gstack-config get proactive 2>/dev/null || echo "true")
 _PROACTIVE_PROMPTED=$([ -f ~/.gstack/.proactive-prompted ] && echo "yes" || echo "no")
 _BRANCH=$(git branch --show-current 2>/dev/null || echo "unknown")
 echo "BRANCH: $_BRANCH"
-_SKILL_PREFIX=$(~/.claude/skills/gstack/bin/gstack-config get skill_prefix 2>/dev/null || echo "false")
+_SKILL_PREFIX=$($HOME/.claude/skills/gstack/bin/gstack-config get skill_prefix 2>/dev/null || echo "false")
 echo "PROACTIVE: $_PROACTIVE"
 echo "PROACTIVE_PROMPTED: $_PROACTIVE_PROMPTED"
 echo "SKILL_PREFIX: $_SKILL_PREFIX"
-source <(~/.claude/skills/gstack/bin/gstack-repo-mode 2>/dev/null) || true
+source <($HOME/.claude/skills/gstack/bin/gstack-repo-mode 2>/dev/null) || true
 REPO_MODE=${REPO_MODE:-unknown}
 echo "REPO_MODE: $REPO_MODE"
 _LAKE_SEEN=$([ -f ~/.gstack/.completeness-intro-seen ] && echo "yes" || echo "no")
 echo "LAKE_INTRO: $_LAKE_SEEN"
-_TEL=$(~/.claude/skills/gstack/bin/gstack-config get telemetry 2>/dev/null || true)
+_TEL=$($HOME/.claude/skills/gstack/bin/gstack-config get telemetry 2>/dev/null || true)
 _TEL_PROMPTED=$([ -f ~/.gstack/.telemetry-prompted ] && echo "yes" || echo "no")
 _TEL_START=$(date +%s)
 _SESSION_ID="$$-$(date +%s)"
 echo "TELEMETRY: ${_TEL:-off}"
 echo "TEL_PROMPTED: $_TEL_PROMPTED"
-_EXPLAIN_LEVEL=$(~/.claude/skills/gstack/bin/gstack-config get explain_level 2>/dev/null || echo "default")
+_EXPLAIN_LEVEL=$($HOME/.claude/skills/gstack/bin/gstack-config get explain_level 2>/dev/null || echo "default")
 if [ "$_EXPLAIN_LEVEL" != "default" ] && [ "$_EXPLAIN_LEVEL" != "terse" ]; then _EXPLAIN_LEVEL="default"; fi
 echo "EXPLAIN_LEVEL: $_EXPLAIN_LEVEL"
-_QUESTION_TUNING=$(~/.claude/skills/gstack/bin/gstack-config get question_tuning 2>/dev/null || echo "false")
+_QUESTION_TUNING=$($HOME/.claude/skills/gstack/bin/gstack-config get question_tuning 2>/dev/null || echo "false")
 echo "QUESTION_TUNING: $_QUESTION_TUNING"
 mkdir -p ~/.gstack/analytics
 if [ "$_TEL" != "off" ]; then
 echo '{"skill":"gstack","ts":"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'","repo":"'$(basename "$(git rev-parse --show-toplevel 2>/dev/null)" 2>/dev/null || echo "unknown")'"}'  >> ~/.gstack/analytics/skill-usage.jsonl 2>/dev/null || true
 fi
 for _PF in $(find ~/.gstack/analytics -maxdepth 1 -name '.pending-*' 2>/dev/null); do
   if [ -f "$_PF" ]; then
-    if [ "$_TEL" != "off" ] && [ -x "~/.claude/skills/gstack/bin/gstack-telemetry-log" ]; then
-      ~/.claude/skills/gstack/bin/gstack-telemetry-log --event-type skill_run --skill _pending_finalize --outcome unknown --session-id "$_SESSION_ID" 2>/dev/null || true
+    if [ "$_TEL" != "off" ] && [ -x "$HOME/.claude/skills/gstack/bin/gstack-telemetry-log" ]; then
+      $HOME/.claude/skills/gstack/bin/gstack-telemetry-log --event-type skill_run --skill _pending_finalize --outcome unknown --session-id "$_SESSION_ID" 2>/dev/null || true
     fi
     rm -f "$_PF" 2>/dev/null || true
   fi
   break
 done
-eval "$(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)" 2>/dev/null || true
+eval "$($HOME/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)" 2>/dev/null || true
 _LEARN_FILE="${GSTACK_HOME:-$HOME/.gstack}/projects/${SLUG:-unknown}/learnings.jsonl"
 if [ -f "$_LEARN_FILE" ]; then
   _LEARN_COUNT=$(wc -l < "$_LEARN_FILE" 2>/dev/null | tr -d ' ')
   echo "LEARNINGS: $_LEARN_COUNT entries loaded"
   if [ "$_LEARN_COUNT" -gt 5 ] 2>/dev/null; then
-    ~/.claude/skills/gstack/bin/gstack-learnings-search --limit 3 2>/dev/null || true
+    $HOME/.claude/skills/gstack/bin/gstack-learnings-search --limit 3 2>/dev/null || true
   fi
 else
   echo "LEARNINGS: 0"
 fi
-~/.claude/skills/gstack/bin/gstack-timeline-log '{"skill":"gstack","event":"started","branch":"'"$_BRANCH"'","session":"'"$_SESSION_ID"'"}' 2>/dev/null &
+$HOME/.claude/skills/gstack/bin/gstack-timeline-log '{"skill":"gstack","event":"started","branch":"'"$_BRANCH"'","session":"'"$_SESSION_ID"'"}' 2>/dev/null &
 _HAS_ROUTING="no"
 if [ -f CLAUDE.md ] && grep -q "## Skill routing" CLAUDE.md 2>/dev/null; then
   _HAS_ROUTING="yes"
 fi
-_ROUTING_DECLINED=$(~/.claude/skills/gstack/bin/gstack-config get routing_declined 2>/dev/null || echo "false")
+_ROUTING_DECLINED=$($HOME/.claude/skills/gstack/bin/gstack-config get routing_declined 2>/dev/null || echo "false")
 echo "HAS_ROUTING: $_HAS_ROUTING"
 echo "ROUTING_DECLINED: $_ROUTING_DECLINED"
 _VENDORED="no"
@@ -94,8 +94,8 @@ if [ -d ".claude/skills/gstack" ] && [ ! -L ".claude/skills/gstack" ]; then
 fi
 echo "VENDORED_GSTACK: $_VENDORED"
 echo "MODEL_OVERLAY: claude"
-_CHECKPOINT_MODE=$(~/.claude/skills/gstack/bin/gstack-config get checkpoint_mode 2>/dev/null || echo "explicit")
-_CHECKPOINT_PUSH=$(~/.claude/skills/gstack/bin/gstack-config get checkpoint_push 2>/dev/null || echo "false")
+_CHECKPOINT_MODE=$($HOME/.claude/skills/gstack/bin/gstack-config get checkpoint_mode 2>/dev/null || echo "explicit")
+_CHECKPOINT_PUSH=$($HOME/.claude/skills/gstack/bin/gstack-config get checkpoint_push 2>/dev/null || echo "false")
 echo "CHECKPOINT_MODE: $_CHECKPOINT_MODE"
 echo "CHECKPOINT_PUSH: $_CHECKPOINT_PUSH"
 [ -n "$OPENCLAW_SESSION" ] && echo "SPAWNED_SESSION: true" || true
@@ -111,15 +111,15 @@ If the user invokes a skill in plan mode, the skill takes precedence over generi
 
 If `PROACTIVE` is `"false"`, do not auto-invoke or proactively suggest skills. If a skill seems useful, ask: "I think /skillname might help here — want me to run it?"
 
-If `SKILL_PREFIX` is `"true"`, suggest/invoke `/gstack-*` names. Disk paths stay `~/.claude/skills/gstack/[skill-name]/SKILL.md`.
+If `SKILL_PREFIX` is `"true"`, suggest/invoke `/gstack-*` names. Disk paths stay `$HOME/.claude/skills/gstack/[skill-name]/SKILL.md`.
 
-If output shows `UPGRADE_AVAILABLE <old> <new>`: read `~/.claude/skills/gstack/gstack-upgrade/SKILL.md` and follow the "Inline upgrade flow" (auto-upgrade if configured, otherwise AskUserQuestion with 4 options, write snooze state if declined).
+If output shows `UPGRADE_AVAILABLE <old> <new>`: read `$HOME/.claude/skills/gstack/gstack-upgrade/SKILL.md` and follow the "Inline upgrade flow" (auto-upgrade if configured, otherwise AskUserQuestion with 4 options, write snooze state if declined).
 
 If output shows `JUST_UPGRADED <from> <to>`: print "Running gstack v{to} (just updated!)". If `SPAWNED_SESSION` is true, skip feature discovery.
 
 Feature discovery, max one prompt per session:
-- Missing `~/.claude/skills/gstack/.feature-prompted-continuous-checkpoint`: AskUserQuestion for Continuous checkpoint auto-commits. If accepted, run `~/.claude/skills/gstack/bin/gstack-config set checkpoint_mode continuous`. Always touch marker.
-- Missing `~/.claude/skills/gstack/.feature-prompted-model-overlay`: inform "Model overlays are active. MODEL_OVERLAY shows the patch." Always touch marker.
+- Missing `$HOME/.claude/skills/gstack/.feature-prompted-continuous-checkpoint`: AskUserQuestion for Continuous checkpoint auto-commits. If accepted, run `$HOME/.claude/skills/gstack/bin/gstack-config set checkpoint_mode continuous`. Always touch marker.
+- Missing `$HOME/.claude/skills/gstack/.feature-prompted-model-overlay`: inform "Model overlays are active. MODEL_OVERLAY shows the patch." Always touch marker.
 
 After upgrade prompts, continue workflow.
 
@@ -132,7 +132,7 @@ Options:
 - B) Restore V0 prose — set `explain_level: terse`
 
 If A: leave `explain_level` unset (defaults to `default`).
-If B: run `~/.claude/skills/gstack/bin/gstack-config set explain_level terse`.
+If B: run `$HOME/.claude/skills/gstack/bin/gstack-config set explain_level terse`.
 
 Always run (regardless of choice):
 ```bash
@@ -159,7 +159,7 @@ Options:
 - A) Help gstack get better! (recommended)
 - B) No thanks
 
-If A: run `~/.claude/skills/gstack/bin/gstack-config set telemetry community`
+If A: run `$HOME/.claude/skills/gstack/bin/gstack-config set telemetry community`
 
 If B: ask follow-up:
 
@@ -169,8 +169,8 @@ Options:
 - A) Sure, anonymous is fine
 - B) No thanks, fully off
 
-If B→A: run `~/.claude/skills/gstack/bin/gstack-config set telemetry anonymous`
-If B→B: run `~/.claude/skills/gstack/bin/gstack-config set telemetry off`
+If B→A: run `$HOME/.claude/skills/gstack/bin/gstack-config set telemetry anonymous`
+If B→B: run `$HOME/.claude/skills/gstack/bin/gstack-config set telemetry off`
 
 Always run:
 ```bash
@@ -187,8 +187,8 @@ Options:
 - A) Keep it on (recommended)
 - B) Turn it off — I'll type /commands myself
 
-If A: run `~/.claude/skills/gstack/bin/gstack-config set proactive true`
-If B: run `~/.claude/skills/gstack/bin/gstack-config set proactive false`
+If A: run `$HOME/.claude/skills/gstack/bin/gstack-config set proactive true`
+If B: run `$HOME/.claude/skills/gstack/bin/gstack-config set proactive false`
 
 Always run:
 ```bash
@@ -233,7 +233,7 @@ Key routing rules:
 
 Then commit the change: `git add CLAUDE.md && git commit -m "chore: add gstack skill routing rules to CLAUDE.md"`
 
-If B: run `~/.claude/skills/gstack/bin/gstack-config set routing_declined true` and say they can re-enable with `gstack-config set routing_declined false`.
+If B: run `$HOME/.claude/skills/gstack/bin/gstack-config set routing_declined true` and say they can re-enable with `gstack-config set routing_declined false`.
 
 This only happens once per project. Skip if `HAS_ROUTING` is `yes` or `ROUTING_DECLINED` is `true`.
 
@@ -249,15 +249,15 @@ Options:
 If A:
 1. Run `git rm -r .claude/skills/gstack/`
 2. Run `echo '.claude/skills/gstack/' >> .gitignore`
-3. Run `~/.claude/skills/gstack/bin/gstack-team-init required` (or `optional`)
+3. Run `$HOME/.claude/skills/gstack/bin/gstack-team-init required` (or `optional`)
 4. Run `git add .claude/ .gitignore CLAUDE.md && git commit -m "chore: migrate gstack from vendored to team mode"`
 5. Tell the user: "Done. Each developer now runs: `cd ~/.claude/skills/gstack && ./setup --team`"
 
 If B: say "OK, you're on your own to keep the vendored copy up to date."
 
 Always run (regardless of choice):
 ```bash
-eval "$(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)" 2>/dev/null || true
+eval "$($HOME/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)" 2>/dev/null || true
 touch ~/.gstack/.vendoring-warned-${SLUG:-unknown}
 ```
 
@@ -281,8 +281,8 @@ if [ -f "$HOME/.gstack-artifacts-remote.txt" ]; then
 else
   _BRAIN_REMOTE_FILE="$HOME/.gstack-brain-remote.txt"
 fi
-_BRAIN_SYNC_BIN="~/.claude/skills/gstack/bin/gstack-brain-sync"
-_BRAIN_CONFIG_BIN="~/.claude/skills/gstack/bin/gstack-config"
+_BRAIN_SYNC_BIN="$HOME/.claude/skills/gstack/bin/gstack-brain-sync"
+_BRAIN_CONFIG_BIN="$HOME/.claude/skills/gstack/bin/gstack-config"
 
 # /sync-gbrain context-load: teach the agent to use gbrain when it's available.
 # Per-worktree pin: post-spike redesign uses kubectl-style `.gbrain-source` in the
@@ -391,8 +391,8 @@ If A/B and `~/.gstack/.git` is missing, ask whether to run `gstack-artifacts-ini
 At skill END before telemetry:
 
 ```bash
-"~/.claude/skills/gstack/bin/gstack-brain-sync" --discover-new 2>/dev/null || true
-"~/.claude/skills/gstack/bin/gstack-brain-sync" --once 2>/dev/null || true
+"$HOME/.claude/skills/gstack/bin/gstack-brain-sync" --discover-new 2>/dev/null || true
+"$HOME/.claude/skills/gstack/bin/gstack-brain-sync" --once 2>/dev/null || true
 ```
 
 
@@ -437,7 +437,7 @@ Escalate after 3 failed attempts, uncertain security-sensitive changes, or scope
 Before completing, if you discovered a durable project quirk or command fix that would save 5+ minutes next time, log it:
 
 ```bash
-~/.claude/skills/gstack/bin/gstack-learnings-log '{"skill":"SKILL_NAME","type":"operational","key":"SHORT_KEY","insight":"DESCRIPTION","confidence":N,"source":"observed"}'
+$HOME/.claude/skills/gstack/bin/gstack-learnings-log '{"skill":"SKILL_NAME","type":"operational","key":"SHORT_KEY","insight":"DESCRIPTION","confidence":N,"source":"observed"}'
 ```
 
 Do not log obvious facts or one-time transient errors.
@@ -541,7 +541,7 @@ Auto-shuts down after 30 min idle. State persists between calls (cookies, tabs,
 _ROOT=$(git rev-parse --show-toplevel 2>/dev/null)
 B=""
 [ -n "$_ROOT" ] && [ -x "$_ROOT/.claude/skills/gstack/browse/dist/browse" ] && B="$_ROOT/.claude/skills/gstack/browse/dist/browse"
-[ -z "$B" ] && B="$HOME/.claude/skills/gstack/browse/dist/browse"
+[ -z "$B" ] && B="$HOME$HOME/.claude/skills/gstack/browse/dist/browse"
 if [ -x "$B" ]; then
   echo "READY: $B"
 else