live: heartbeat sync 2026-10-21T02:32:51-07:00 (Refs #11)

agent/managed-skills/gitignore-trailing-slash-symlink-contamination/SKILL.md

@@ -1,41 +1,48 @@
 ---
 name: gitignore-trailing-slash-symlink-contamination
-description: "Trailing-slash gitignore rules don't match symlinks, so worktree dependency symlinks get committed; detect with git ls-tree mode 120000, fix with git rm --cached."
+description: "Trailing-slash gitignore rules don't match symlinks, so worktree dependency symlinks get tracked and pushed as 1-line blobs; same-name rules silently match worktree dirs, and .deploy-stale pollutes. Three fixes with tests."
 ---
 
-A `.gitignore` entry written with a **trailing slash matches directories only**. A symlink of the same name is not a directory, so it slips past the rule, and `git add -A` in a `git worktree` checkout silently **tracks** it. Cost measured 2026-10-19: a machine-specific symlink (`node_modules -> /home/blank/Projects/dankvoice/node_modules`) landed in `main` with a merged PR.
+Gitignore semantics trap with three real-world consequences (serverAppConfigs, 2026-10-19):
 
-Why worktrees are the trigger: a worktree has no `node_modules` (or other installed-deps dir) of its own, so the cheap way to make build/test work there is a symlink into the primary checkout. With `node_modules/` ignored, nothing complains.
+## The rule
 
-## Detect
+`.gitignore` patterns ending in `/` match directories only. Worktree-relative: `**/node_modules/` is `**/node_modules/` → a symlink named `node_modules` does NOT match, so it is "untracked" no more — it gets added, committed, and pushed as a 1-line blob containing its target path.
+
+## Consequence 1: worktree symlink contamination
+
+- `git add -A` then commit then push in a worktree whose root holds `node_modules -> ...` (the worktree convention symlink) commits it.
+- The repo then holds `package/frontend/node_modules` as a text file containing the absolute path on the author's box.
+- The receiving worktree gets that 1-line file instead of the symlink → "module not found" and "why is this a 30-byte file?".
+- Detection: `git ls-tree -r origin/main | awk '$1=="120000"'` (mode 120000 = symlink) or `git ls-files -s | grep 120000`.
+- Fix: ignore rules WITHOUT trailing slash (`**/node_modules`, `**/.venv`) so symlinks match too.
+
+## Consequence 2: same-name worktree rules silently matching worktree dirs
+
+A root rule like `wt-*` (meant to ignore local worktree checkouts) matches every path whose last segment starts with `wt-` — so legitimate content under such a directory goes untracked. `git status --ignored` is the only visible trace; detection: `git check-ignore -v <path>` prints the owning rule + line number. (Repo-specific: `dank/command-center`'s `.gitignore` carries a "per-worktree memory buckets" block ignoring `agent/memories/sharpshooter/wt-*/` and `agent/memories/summaries/wt-*/` — intentional there.)
+
+## Consequence 3: `.deploy-stale`
+
+`deploy.sh` renames a stale tree to `<path>.deploy-stale` before recreating it. Without an ignore rule those directories land in `git status` as untracked and get swept into `git add -A` commits; they accumulate on every server.
+
+## Fixes with tests
+
+```gitignore
+**/node_modules
+**/.venv
+.deploy-stale/
+```
+
+Black-box test against the real rules, not a fixture: `git check-ignore -v <symlink-target>` must name the rule. `git check-ignore` takes hypothetical paths — nothing needs to exist on disk:
 
 ```bash
-git ls-tree HEAD -- node_modules          # mode 120000 == tracked symlink
-git ls-files -s | awk '$1==120000'        # every tracked symlink in the index
+git check-ignore -v natives/x.wasm dotfiles/x/.config/noctalia/Noctalia.json
 ```
 
-## Fix (branch, never on main directly)
+Two ignore surfaces must be kept in sync (deploy exclusions vs ignore rules): if a deployer excludes `*/Noctalia*` but the ignore list has only the lowercase class, generated files become tracked-but-never-deployed — test both halves with `git check-ignore`.
 
-```bash
-git rm -q --cached node_modules           # untrack; leaves the file on disk
-```
+## Recovery (if contamination already pushed)
 
-plus relax the ignore rule to the slash-free form, with the reason inline so nobody re-adds the slash:
-
-```
-# Trailing slash would only match directories: a node_modules symlink (the
-# shape `git worktree` checkouts end up with) slips past it and gets tracked.
-node_modules
-```
-
-Then `git check-ignore -v node_modules` must print the rule, and the suite runs after (the symlink still resolves, it is just ignored).
-
-## Prevent
-
-In a fresh worktree, create the deps symlink **after** confirming the ignore rule has no trailing slash:
-
-```bash
-git check-ignore -v node_modules || sed -i 's|^node_modules/$|node_modules|' .gitignore
-```
-
-Same class for any ignored-by-convention dir that a worktree might provide as a link: `node_modules`, `vendor`, `.venv`, `target`, `dist` when built artifacts are ignored.
+1. `git rm --cached <path>` on the symlink blob, commit, push.
+2. Fix the ignore rule first (else the next `git add -A` re-adds it).
+3. Untracked ≠ deleted from history: the blob stays in every old commit. Only a rewrite removes it; that is the operator's call, not a cleanup run alone.