fix(sync): point sync.sh at this repo's plugin cache, not the private repo's (#402)

sync.sh was written against the layout of mvanhorn/last30days-skill-private
(`.../cache/last30days-skill-private/last30days-3/{version}`) and that path
was never updated when this public repo got its own copy. Running sync.sh
from here populated the BETA channel's cache (`/last30days-beta`) instead
of this repo's own `/last30days` cache, so devs working in this repo could
not test their changes via the public slash command without waiting for a
marketplace release.

Path now derives from this repo's own manifests:
- marketplace name `last30days-skill` (.claude-plugin/marketplace.json)
- plugin name      `last30days`       (.claude-plugin/plugin.json)

Drops the `last30days-3-nogem` target along with it - that's a private-repo
variant with no public equivalent.

Updates test_sync_cache_path_uses_skill_version to assert the new path
pattern and clarifies the COMMON_TARGETS comment so the next person editing
it understands which marketplace/plugin name segments come from where.

skills/last30days/scripts/sync.sh

@@ -7,12 +7,15 @@ SRC="$(cd "$(dirname "$0")/.." && pwd)"
 echo "Source: $SRC"
 
 COMMON_TARGETS=(
-  # Claude Code plugin cache: marketplace installs overwrite on update,
-  # but local development needs the cache kept in sync with the repo.
-  # Do NOT add ~/.claude/skills/last30days - it creates a duplicate
-  # /last30days-3 in the slash command menu alongside the plugin version.
-  "$HOME/.claude/plugins/cache/last30days-skill-private/last30days-3/3.2.1"
-  "$HOME/.claude/plugins/cache/last30days-skill-private/last30days-3-nogem/3.0.0-nogem"
+  # Claude Code plugin cache for this (public) repo's marketplace install.
+  # Marketplace name = last30days-skill (.claude-plugin/marketplace.json).
+  # Plugin name      = last30days       (.claude-plugin/plugin.json).
+  # Path shape       = .../cache/{marketplace-name}/{plugin-name}/{version}.
+  # Marketplace pulls overwrite this on update; local sync keeps it fresh
+  # against the working tree so /last30days reflects local dev without
+  # waiting for a release. Do NOT add ~/.claude/skills/last30days - it
+  # creates a duplicate slash-command entry alongside the plugin version.
+  "$HOME/.claude/plugins/cache/last30days-skill/last30days/3.2.1"
   "$HOME/.agents/skills/last30days"
   "$HOME/.codex/skills/last30days"
 )

tests/test_version_consistency.py

@@ -24,7 +24,10 @@ class TestVersionConsistency(unittest.TestCase):
     def test_sync_cache_path_uses_skill_version(self) -> None:
         sync_text = (SKILL_ROOT / "scripts" / "sync.sh").read_text(encoding="utf-8")
         version = _skill_version()
-        self.assertIn(f'last30days-3/{version}"', sync_text)
+        self.assertIn(
+            f'last30days-skill/last30days/{version}"',
+            sync_text,
+        )
 
     def test_memory_save_dir_uses_single_env_variable(self) -> None:
         skill_text = (SKILL_ROOT / "SKILL.md").read_text(encoding="utf-8")