fix: gstack-slug bash compatibility — source to eval (#354)

* fix: replace source <(gstack-slug) with eval for bash compatibility

Under bash with set -euo pipefail, source <(cmd) process substitution
doesn't reliably set variables in the caller's scope. The variables
stay empty and -u (nounset) crashes the script. eval "$(cmd)" works
correctly in both bash and zsh.

Fixes: gstack-review-read, gstack-review-log, gstack-slug comment,
gen-skill-docs.ts resolver functions, and regression tests.

* chore: bump version and changelog (v0.11.4.0)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

design-consultation/SKILL.md

@@ -327,7 +327,7 @@ ls src/ app/ pages/ components/ 2>/dev/null | head -30
 Look for office-hours output:
 
 ```bash
-source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
+eval "$(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)"
 ls ~/.gstack/projects/$SLUG/*office-hours* 2>/dev/null | head -5
 ls .context/*office-hours* .context/attachments/*office-hours* 2>/dev/null | head -5
 ```

design-consultation/SKILL.md.tmpl

@@ -52,7 +52,7 @@ ls src/ app/ pages/ components/ 2>/dev/null | head -30
 Look for office-hours output:
 
 ```bash
-source <(~/.claude/skills/gstack/bin/gstack-slug 2>/dev/null)
+{{SLUG_EVAL}}
 ls ~/.gstack/projects/$SLUG/*office-hours* 2>/dev/null | head -5
 ls .context/*office-hours* .context/attachments/*office-hours* 2>/dev/null | head -5
 ```