refactor: turn the repo into a two-plugin marketplace

tea and tdl were two repositories, each carrying its own
.claude-plugin/marketplace.json — two marketplaces to register for what
is one collection. Fold them into one.

The repo root is now the marketplace and nothing else: a single
.claude-plugin/marketplace.json whose entries point at ./plugins/tea and
./plugins/tdl. A plugin's root is its own directory under plugins/, so
${CLAUDE_PLUGIN_ROOT} still resolves inside it and every path a plugin
uses stays relative to itself — the hooks and the test roots needed no
adjustment beyond the move.

tea's files move with git mv, so its history and blame follow. tdl
arrives as a plain copy; its history stays in claude-skills/threedotslab.

test_payload_root asserted `tmp/` was ignored by REPO/.gitignore. The
rule is that tmp/ is ignored, not which file says so, and git reads every
.gitignore on the way up — so the test now walks up to the repo root the
same way git does.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

plugins/tea/hooks/hooks.json

@@ -0,0 +1,19 @@
+{
+  "hooks": {
+    "PreToolUse": [
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "${CLAUDE_PLUGIN_ROOT}/hooks/agents-sync.sh"
+          },
+          {
+            "type": "command",
+            "command": "${CLAUDE_PLUGIN_ROOT}/hooks/tea-guard.sh"
+          }
+        ]
+      }
+    ]
+  }
+}