feat(pi): add skills and improve AGENTS.md reading guidelines

- Add 'create-skill' skill for scaffolding new skill directories
- Add 'planning' skill for structured implementation workflows
- Add search-then-read pattern guidance to AGENTS.md

modules/home/programs/terminal/pi/config/skills/create-skill/SKILL.md

@@ -0,0 +1,53 @@
+---
+name: create-skill
+description: 'Create a new skill in the skills directory. Use when user asks to add a skill, create a skill, or mentions "/create-skill". Produces a SKILL.md with frontmatter and optional helper scripts, following conventions from existing skills.'
+---
+
+# Create Skill
+
+## Overview
+
+Scaffold a new skill directory with a `SKILL.md` and optional helper scripts under the project's skills directory.
+
+## Workflow
+
+### 1. Gather Requirements
+
+Ask the user:
+- **What does the skill do?** (trigger conditions, purpose)
+- **Are there repeatable commands?** (if yes, these become scripts)
+
+If the user already provided enough detail, skip straight to drafting.
+
+### 2. Draft the Skill
+
+Create `skills/<skill-name>/SKILL.md` with this structure:
+
+```markdown
+---
+name: <skill-name>
+description: '<One-liner: what it does and when to trigger. Keep under ~200 chars.>'
+---
+
+# <Skill Title>
+
+## Overview
+[1-2 sentences on purpose and scope]
+
+## Workflow
+[Numbered steps the agent follows]
+```
+
+**Guidelines:**
+- **Be concise.** Skills are injected into agent context — every line costs tokens. Aim for the minimum needed to reliably guide the agent.
+- **Use scripts for repeatable logic.** If a step involves a multi-line shell command, `jq` pipeline, or API call that won't change between runs, put it in a `.sh` file next to `SKILL.md` and reference it from the workflow. See `address-gh-review/` for an example.
+- **Frontmatter is required.** `name` and `description` fields. The description is what the agent uses to decide whether to load the skill, so make it specific about trigger conditions.
+- **Don't over-specify.** Trust the agent to fill gaps. Document the _what_ and _when_, not every micro-step.
+
+### 3. Present for Review
+
+Show the user the draft and wait for approval before finalizing. Apply any requested changes.
+
+### 4. Git Add
+
+Run `git add` on the new skill directory so the flake/tooling can discover it.