fix(orchestrator): S1 fit, rename once, Deutschlandfunk e2e, squelch, tree cause

Requirement 001 phase 6, S1:

- Fit: Agents and Artifacts in a graph view fill the window from 861 px
  up (body.fit flex column); the e2e walk probes #agents/orbit at every
  width for a page no taller than the window.
- Rename once: a session seen under two names by one source (two claims)
  flipped its name on every state build, so the Stream logged a rename
  each poll. Names.observe keeps only the newest sighting per session
  and source, and the timeline emits each (session, before, after) pair
  once.
- Deutschlandfunk: root cause was the signed media-src, which never
  listed the redirect target f111.rndfnk.com that st01.sslstream.dlf.de
  answers with (fixed in ba97f7c). The e2e now replays that chain, a
  302 from one https origin to a second, in Chromium and Firefox, with
  self-signed throwaway certificates the drivers accept.
- Squelch: a settings slider 0..1 scales every tone; at 0 no beep plays,
  music on or off (Voice.beep skips a silent tone). Stored settings
  without the key load with 1.0.
- Tree: the missing tree file error names `pkgmgr branch tree` and the
  release and install step that makes the timer write it.

Evidence: make test 655 OK, ruff and markdownlint clean
(/tmp/s1-make-test-1.log); e2e 17 OK, none skipped (/tmp/s1-e2e-3.log);
MEDUSA 14 files, 0 findings.

🎯 Fix: 94 %
💥 Break: 4 %
💸 Cost: 100 %
⏱️ Time: –
🛡️ Security: 100 %
🏆 Score: 90
🚦 Gate: ✅ 90/5, cost and time <= 100, security 100 %

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

orchestrator/templates/index.html.j2

@@ -209,6 +209,14 @@ table.diff tr.more td { padding: 8px 16px; color: var(--muted); font-style: ital
 .graph-body { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 14px; align-items: start; }
 .stage-card { padding: 8px; }
 .stage svg { display: block; width: 100%; height: auto; max-height: calc(100vh - var(--head) - 120px); }
+@media (min-width: 861px) {
+  body.fit { display: flex; flex-direction: column; height: 100vh; }
+  body.fit .shell, body.fit main, body.fit .graph, body.fit .stage-card, body.fit .stage { display: flex; flex: 1; flex-direction: column; min-height: 0; }
+  body.fit main { padding-bottom: var(--sp-5); }
+  body.fit .graph-body { flex: 1; align-items: stretch; min-height: 0; }
+  body.fit .stage svg, body.fit .stage canvas.space, body.fit .graph3d { flex: 1; height: auto; min-height: 0; max-height: none; }
+  body.fit .panel { position: static; max-height: none; min-height: 0; overflow: auto; }
+}
 .legend { display: flex; flex-wrap: wrap; gap: 6px 16px; padding: 6px 10px 4px; color: var(--muted); font-size: var(--fs-sm); }
 .legend span { display: inline-flex; align-items: center; gap: 6px; }
 .swatch { display: inline-block; width: 18px; height: 4px; border-radius: 2px; background: var(--c); }