chore(gitignore): treat tag_catalog.yaml and smart-test locks as runtime cache

Two untracked files were blocking release prep without a clear reason
to commit them:

- .agent/tracker/tag_catalog.yaml is the catalog populated lazily by
  the WI-lifal `tracker tags` subcommand. Its current contents are
  pure cache (every entry has empty description, false deprecated,
  null in_favor_of) and every field present is derivable from the op
  log per the WI-lifal commit message. Committing it would create
  merge-conflict churn on `last_used` timestamps every time any agent
  ran the subcommand, with zero information gain. Sibling to
  `.agent/tracker-workspace/tui_preferences.json`. WI-lagid filed for
  the design follow-up of where `tags describe` / `tags deprecate`
  editorial state should persist when someone actually uses those
  verbs.

- .ci/.smart-test.lock and .ci/.smart-test.lock.pid are process-local
  runtime locks that smart-test creates and reuses across runs. They
  were never meant to be committed; matches the existing
  `full-suite.log` pattern in .ci/.gitignore.

Signed-off-by: jgstern-agent <josh-agent@iterabloom.com>

Author: jgstern-agent

.agent/tracker/.gitignore

@@ -1 +1,2 @@
 config.yaml
+tag_catalog.yaml

.ci/.gitignore

@@ -1,2 +1,6 @@
 # CI artifacts - logs are ignored, manifests are committed
 full-suite.log
+
+# smart-test runtime locks (process-local, never committed)
+.smart-test.lock
+.smart-test.lock.pid

.ci/affected-tests.txt

@@ -1,9 +1,9 @@
 # Test selection manifest
-# Generated by smart-test at 2026-04-29T03:20:32-04:00
+# Generated by smart-test at 2026-04-29T03:48:54-04:00
 # Mode: targeted
-# Baseline: c1c7273072599963c0425c9a84a5b2541062f46f
+# Baseline: f27d01b7a4d56bbb329c4d77db125e8aa8b9c501
 # Reason: no Python source files changed
-# Changed files: 3
+# Changed files: 2
 # Changed source files: 0
 # Selected tests: 0
 #