fix: lint errors and add /search docs

oops, forgot to document the /search command and had some lint issues:
- removed unused imports
- fixed template literal type issues
- documented /search in slash-commands.md

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/tools/slash-commands.md

@@ -61,7 +61,8 @@ Text + native (when enabled):
 - `/skill <name> [input]` (run a skill by name)
 - `/status` (show current status; includes provider usage/quota for the current model provider when available)
 - `/allowlist` (list/add/remove allowlist entries)
-- `/context [list|detail|json]` (explain “context”; `detail` shows per-file + per-tool + per-skill + system prompt size)
+- `/search <query> [--from <contact>] [--platform <name>] [--since <time>]` (search messages across platforms)
+- `/context [list|detail|json]` (explain "context"; `detail` shows per-file + per-tool + per-skill + system prompt size)
 - `/whoami` (show your sender id; alias: `/id`)
 - `/subagents list|stop|log|info|send` (inspect, stop, log, or message sub-agent runs for the current session)
 - `/config show|get|set|unset` (persist config to disk, owner-only; requires `commands.config: true`)