feat(install): add Mistral Vibe wiring target (parity with local-dev)

Ports the Vibe wiring from local-dev's wire-skills.sh so this repo's installer
covers all four harnesses. Vibe uses a flat layout — ~/.vibe/skills/<name>.md
symlinked to the skill's SKILL.md file (not the directory, unlike Claude/Crush/
Antigravity). Added to both `task install` and install.sh, idempotent.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Taskfile.yml

@@ -14,6 +14,7 @@ vars:
   CLAUDE_GLOBAL_DIR: '{{.HOME}}/.claude/skills'
   CRUSH_DIR: '{{.HOME}}/.config/crush/skills'
   ANTIGRAVITY_DIR: '{{.HOME}}/.gemini/antigravity/skills'
+  VIBE_DIR: '{{.HOME}}/.vibe/skills'
   # Anything at the repo root that is NOT a skill directory. Both
   # Taskfile + install.sh share this exclusion regex.
   NON_SKILL_ENTRIES: '^(Taskfile.yml|install.sh|README.md|SKILLS_INDEX.md|.gitea|.git$)$'
@@ -31,12 +32,13 @@ tasks:
     silent: true
 
   install:
-    desc: 'Wire skills into every supported harness (Claude Code, Crush, Antigravity).'
+    desc: 'Wire skills into every supported harness (Claude Code, Crush, Antigravity, Mistral Vibe).'
     cmds:
       - task: install:claude:global
       - task: install:claude:repo
       - task: install:crush
       - task: install:antigravity
+      - task: install:vibe
 
   install:claude:global:
     desc: 'Per-skill symlinks under ~/.claude/skills/<name> — visible in every Claude Code project on this host.'
@@ -122,6 +124,26 @@ tasks:
           echo "linked $link → $target"
         done
 
+  install:vibe:
+    desc: 'Per-skill file symlinks under ~/.vibe/skills/<name>.md → <skill>/SKILL.md for Mistral Vibe (flat .md layout, not a directory).'
+    cmds:
+      - mkdir -p {{.VIBE_DIR}}
+      - |
+        for skill in $(ls -1 "{{.TASKFILE_DIR}}" | grep -Ev "{{.NON_SKILL_ENTRIES}}"); do
+          target="{{.TASKFILE_DIR}}/${skill}/SKILL.md"
+          [ -f "$target" ] || continue
+          link="{{.VIBE_DIR}}/${skill}.md"
+          if [ -L "$link" ] || [ -e "$link" ]; then
+            current=$(readlink "$link" 2>/dev/null || true)
+            if [ "$current" = "$target" ]; then
+              continue
+            fi
+            rm -rf "$link"
+          fi
+          ln -s "$target" "$link"
+          echo "linked $link → $target"
+        done
+
   update:
     desc: 'git pull the canonical checkout then re-run install.'
     cmds: