Use Gitea milestones for goal tracking instead of vision issue

Refactored the vision system to separate concerns:
- vision.md remains the stable "north star" philosophy document
- Gitea milestones now track goals with automatic progress via issue counts
- Updated /vision, /retro, and /create-issue commands to auto-assign milestones

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

commands/create-issue.md

@@ -7,13 +7,34 @@ argument-hint: [title] or "batch"
 
 @~/.claude/skills/gitea/SKILL.md
 
+## Milestone Assignment
+
+Before creating issues, fetch available milestones:
+
+```bash
+tea milestones -f title,description
+```
+
+For each issue, automatically assign to the most relevant milestone by matching:
+- Issue content/problem area → Milestone title and description
+- If no clear match, ask the user which milestone (goal) the issue supports
+- If no milestones exist, skip milestone assignment
+
+Include `--milestone "<milestone>"` in the create command when a milestone is assigned.
+
 ## Single Issue (default)
-If title provided, create an issue with that title and ask for description.
+
+If title provided:
+1. Create an issue with that title
+2. Ask for description
+3. Assign to appropriate milestone (see above)
 
 ## Batch Mode
+
 If $1 is "batch":
 1. Ask user for the plan/direction
-2. Generate list of issues with titles and descriptions
-3. Show for approval
-4. Create each issue
-5. Display all created issue numbers
+2. Fetch available milestones
+3. Generate list of issues with titles, descriptions, and milestone assignments
+4. Show for approval
+5. Create each issue with milestone
+6. Display all created issue numbers