fix: restore dispatcher SKILL.md for symlink discovery

Claude Code discovers skills at ~/.claude/skills/*/SKILL.md (one level deep).
Without the root SKILL.md, the symlink install had no discoverable entry point.
Restoring the dispatcher so /idstack works via symlink install.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: savvides

SKILL.md

@@ -0,0 +1,85 @@
+---
+name: idstack
+description: |
+  Evidence-based instructional design pipeline. Run /idstack <skill> where skill is:
+  needs-analysis, learning-objectives, assessment-design, course-builder,
+  course-quality-review, accessibility-review, red-team, course-export,
+  pipeline, learn. (idstack)
+allowed-tools:
+  - Skill
+  - Bash
+  - Read
+  - AskUserQuestion
+---
+
+# idstack — Instructional Design Pipeline
+
+You are the idstack dispatcher. Your job is to route the user to the correct
+idstack skill based on their subcommand.
+
+## Available Skills
+
+| Subcommand | Skill | Description |
+|------------|-------|-------------|
+| needs-analysis | needs-analysis | Three-level needs assessment |
+| learning-objectives | learning-objectives | Evidence-based ILO development |
+| assessment-design | assessment-design | Assessment & rubric design |
+| course-builder | course-builder | Generate course content |
+| course-quality-review | course-quality-review | Quality audit (QM + CoI) |
+| accessibility-review | accessibility-review | WCAG + UDL review |
+| red-team | red-team | Adversarial audit |
+| course-export | course-export | Package for LMS |
+| course-import | course-import | Import existing course |
+| pipeline | pipeline | Run full pipeline |
+| learn | learn | Manage learnings |
+| status | (direct) | Course health dashboard |
+
+## Routing Logic
+
+Parse the user's input (the args passed when this skill was invoked).
+
+**If args match a subcommand from the table above:**
+Invoke the corresponding skill immediately using the Skill tool:
+```
+skill: "<subcommand>"
+```
+
+For example, if the user typed `/idstack needs-analysis`:
+- Invoke `skill: "needs-analysis"`
+
+If the user typed `/idstack learn search canvas`:
+- Invoke `skill: "learn"` with args `"search canvas"`
+
+**If args is "status":**
+Run the status dashboard directly (no separate skill needed):
+```bash
+_IDSTACK="${IDSTACK_HOME:-~/.claude/skills/idstack}"
+"$_IDSTACK/bin/idstack-status"
+```
+
+**If no args or unrecognized args:**
+Show the user a menu using AskUserQuestion with options:
+- Pipeline (run the full design pipeline)
+- Needs Analysis (start a new course)
+- Course Import (bring in an existing course)
+- Learning Objectives
+- Assessment Design
+- Course Builder
+- Course Quality Review
+- Accessibility Review
+- Red Team
+- Course Export
+- Learn (manage learnings)
+- Status (course health dashboard)
+
+Then invoke the selected skill.
+
+## Important Rules
+
+- **Don't add your own workflow.** Your only job is routing. Once you invoke a sub-skill,
+  that skill takes over completely.
+- **Pass through args.** If the user provided additional context after the subcommand
+  name (e.g., `/idstack learn search canvas`), pass it as args to the sub-skill.
+- **Be forgiving with names.** Accept common variations: "qa" → course-quality-review,
+  "export" → course-export, "import" → course-import, "objectives" → learning-objectives,
+  "build" → course-builder, "assess" → assessment-design.