t3-provision-users: vendor agent skills + per-user install_skills (emo)

Make the admin's Claude Code agent skills available to the `emo` devvm user.
Viktor asked to install Matt Pocock's skills for emo, starting with grill-me
but covering the full set the admin already uses.

The `npx skills` upstream has drifted off that set (diagnose -> diagnosing-bugs
and write-a-skill -> writing-great-skills were renamed; caveman + zoom-out are
no longer published), so reproducing it via npx is impossible and would also
spray ~70 agent dirs into the user's home + add a GitHub-clone + unpinned-CLI
dependency to the hourly root reconcile. Instead vendor a point-in-time
snapshot of the 16 skills (scripts/workstation/claude-skills/) and copy them
per-user, mirroring install_memory: install_skills() copies each skill into
~/.agents/skills/<name> (owned by the user) and symlinks
~/.claude/skills/<name> -> ../../.agents/skills/<name>. if-absent, additive,
best-effort, scoped to the SKILL_USERS allowlist (emo).

find-skills is from vercel-labs/skills (not Matt Pocock) but included since it
is part of the admin's current set.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scripts/workstation/claude-skills/teach/LEARNING-RECORD-FORMAT.md

@@ -0,0 +1,46 @@
+# Learning Record Format
+
+Learning records live in `./learning-records/` and use sequential numbering: `0001-slug.md`, `0002-slug.md`, etc. Create the directory lazily — only when the first record is written.
+
+They are the teaching equivalent of ADRs: they capture non-obvious lessons, key insights, and stated prior knowledge that will steer future sessions. They are used to calculate the zone of proximal development.
+
+## Template
+
+```md
+# {Short title of what was learned or established}
+
+{1-3 sentences: what was learned (or what prior knowledge was established), and why it matters for future sessions.}
+```
+
+That is the whole format. A learning record can be a single paragraph. The value is recording _that_ this is now known and _why_ it changes what to teach next — not in filling out sections.
+
+## Optional sections
+
+Only include these when they add genuine value. Most records won't need them.
+
+- **Status** frontmatter (`active | superseded by LR-NNNN`) — useful when an earlier understanding turns out to be wrong and is replaced.
+- **Evidence** — how the user demonstrated the understanding (a question answered, an exercise completed, prior experience cited). Useful when the claim might be revisited.
+- **Implications** — what this unlocks or rules out for future sessions. Worth recording when non-obvious.
+
+## Numbering
+
+Scan `./learning-records/` for the highest existing number and increment by one.
+
+## When to write a learning record
+
+Write one when any of these is true:
+
+1. **The user demonstrated genuine understanding of something non-trivial** — not just exposure, but evidence they can use the concept correctly. This sets a new floor for what to teach next.
+2. **The user disclosed prior knowledge** — "I already know X." Record it so future sessions don't re-teach it. Also record the _depth_ claimed.
+3. **A misconception was corrected** — the user previously believed something wrong and now sees why. These are high-value: they predict future stumbling blocks for related topics.
+4. **The mission shifted in response to learning** — the user discovered they cared about something different than they thought. Cross-link to [[MISSION.md]] and update it.
+
+### What does _not_ qualify
+
+- Material that was merely covered. Coverage is not learning. Wait for evidence.
+- Anything already captured tersely in [[GLOSSARY.md]] as a term definition. Don't duplicate.
+- Session-by-session activity logs. Learning records are not a journal — they are decision-grade insights.
+
+## Supersession
+
+When a later record contradicts an earlier one (the user's understanding deepened or corrected), mark the old record `Status: superseded by LR-NNNN` rather than deleting it. The history of how understanding evolved is itself useful signal.