feat(retro): surface logical SLOC + weighted commits above raw LOC

V1 reorders the /retro summary table to lead with features shipped,
then commits + weighted commits (commits × files-touched capped at 20),
then PRs merged, then logical SLOC added as the primary code-volume
metric. Raw LOC stays present but is demoted to context. Rationale
inline in the template: ten lines of a good fix is not less shipping
than ten thousand lines of scaffold.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

retro/SKILL.md.tmpl

@@ -139,21 +139,30 @@ Calculate and present these metrics in a summary table:
 
 | Metric | Value |
 |--------|-------|
+| **Features shipped** (from CHANGELOG + merged PR titles) | N |
 | Commits to main | N |
+| Weighted commits (commits × avg files-touched, capped at 20 per commit) | N |
 | Contributors | N |
 | PRs merged | N |
-| Total insertions | N |
-| Total deletions | N |
-| Net LOC added | N |
+| **Logical SLOC added** (non-blank, non-comment — primary code-volume metric) | N |
+| Raw LOC: insertions | N |
+| Raw LOC: deletions | N |
+| Raw LOC: net | N |
 | Test LOC (insertions) | N |
 | Test LOC ratio | N% |
 | Version range | vX.Y.Z.W → vX.Y.Z.W |
 | Active days | N |
 | Detected sessions | N |
-| Avg LOC/session-hour | N |
+| Avg raw LOC/session-hour | N |
 | Greptile signal | N% (Y catches, Z FPs) |
 | Test Health | N total tests · M added this period · K regression tests |
 
+**Metric order rationale (V1):** features shipped leads — what users got. Commits
+and weighted commits reflect intent-to-ship. Logical SLOC added reflects real
+new functionality. Raw LOC is demoted to context because AI inflates it; ten
+lines of a good fix is not less shipping than ten thousand lines of scaffold.
+See docs/designs/PLAN_TUNING_V1.md §Workstream C.
+
 Then show a **per-author leaderboard** immediately below:
 
 ```