fix: cover tui in the CLI inventory and drop the em-dashes it printed

The inventory test predates the `tui` command, so a rename or an
accidental removal would have gone unnoticed: it now asserts the command,
its `-l`/`--list` flag and its optional position operand.

The digest and search-result lines joined their halves with an em-dash,
which the repo's own convention rules out, so both now use the middle dot
the surrounding lines already use. The one em-dash left in `src/tui/` is
load-bearing: `search-service.ts` builds a session snippet with it, and
the pattern that strips the repeated label has to match it.

Also moves `buildSearchEntries`'s doc comment back onto
`buildSearchEntries`; it had ended up stacked above a helper.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/tui/tui-digest.test.ts

@@ -75,7 +75,7 @@ describe('formatAwayDigest', () => {
       { now: NOW }
     );
     expect(lines).toContain('NEEDS ATTENTION (1)');
-    expect(lines).toContain('  2m   w4-api  permission prompt — Bash(git push)');
+    expect(lines).toContain('  2m   w4-api  permission prompt · Bash(git push)');
   });
 
   it('caps a long section instead of burying the next one', () => {