Add vision-driven continuous improvement to product-manager

Transforms the product-manager from a reactive backlog manager into a
vision-driven system with continuous improvement capabilities.

New components:
- vision-management skill: How to create, maintain, and evolve product vision
- /vision command: View, create, or update product vision (syncs to Gitea)
- /improve command: Identify gaps between vision goals and backlog

Enhanced existing components:
- product-manager agent: Now vision-aware with strategic prioritization
- /retro command: Connects learnings back to vision updates
- /plan-issues command: Shows vision alignment for planned work

The vision lives in two places: vision.md (source of truth) and a Gitea
issue labeled "vision" for integration with the issue workflow.

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

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

commands/vision.md

@@ -0,0 +1,72 @@
+---
+description: View, create, or update the product vision. Manages vision.md and syncs to Gitea.
+argument-hint: [update|goals|focus]
+---
+
+# Product Vision
+
+@~/.claude/skills/vision-management/SKILL.md
+@~/.claude/skills/gitea/SKILL.md
+
+## Process
+
+1. **Check for existing vision**: Look for `vision.md` in the current repo root.
+
+2. **If no vision exists**:
+   - Ask the user if they want to create one
+   - Guide them through:
+     - Purpose: Why does this product exist?
+     - Goals: 3-5 measurable outcomes with success metrics
+     - Current focus: Which 1-2 goals are priorities now?
+     - Non-goals: What are you explicitly NOT doing?
+   - Create `vision.md` with the vision document structure
+   - Create a Gitea issue labeled `vision` with the same content
+
+3. **If vision exists**:
+   - Display the current vision
+   - Check if $1 specifies an action:
+     - `update`: General update to the vision
+     - `goals`: Add, modify, or complete goals
+     - `focus`: Change the current focus area
+   - If no action specified, ask what the user wants to do:
+     - View only (done)
+     - Update goals
+     - Change focus
+     - Update progress
+     - Add non-goals
+   - Make the requested changes
+   - Update `vision.md`
+   - Sync changes to the Gitea vision issue
+
+4. **Sync to Gitea**:
+   - Find existing issue with `vision` label: `tea issues -l vision`
+   - If exists: Update the issue description
+   - If not: Create new issue with `vision` label
+
+## Output Format
+
+When displaying the vision, show it clearly:
+
+```
+## Current Vision
+
+**Purpose**: [purpose]
+
+**Goals**:
+1. [Goal] - [Metric] [Progress indicator]
+2. [Goal] - [Metric] [Progress indicator]
+
+**Current Focus**: [focus area]
+
+**Non-Goals**: [list]
+
+**Last Updated**: [date]
+```
+
+## Guidelines
+
+- Keep goals specific and measurable
+- Limit to 3-5 active goals
+- Current focus should be 1-2 goals max
+- Update "Last Updated" on every change
+- Always sync to Gitea after changes