fix(content): record peer transport on cloud browse/download/preview (B14)

The 4 content peer handlers (browse, download, download_paid, preview)
captured the transport returned by PeerRequest::send_get() but discarded
it, so the federation node's last_transport was never updated for cloud
activity — the UI showed Tor/none even when FIPS was used. Call
record_peer_transport() after each successful fetch (same as sync does).

Note: live data shows FIPS still reaches only some peers (many genuinely
fall back to Tor) — tracked separately as B14b (FIPS reachability).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/production-quality/TRACKER.md

@@ -59,7 +59,7 @@ Music/video preview files on peer nodes' cloud don't play (streaming/range/conte
 ### B4 — Cloud "my folders" fails (JSON parse / 502) — PASSED (content-type guard; built, guard in bundle, deployed .198). UI visual-confirm recommended.
 `Unexpected token '<', "<!doctype"` when FileBrowser absent (`/app/filebrowser/api/resources` → SPA index.html), and **502** when FileBrowser is down (seen on .103). filebrowser-client.ts:102/:106. Fix: detect FileBrowser unavailable, friendly prompt; consider nginx returning JSON 404/502 for missing `/app/<app>/` instead of SPA shell. Handle BOTH absent + down.
 
-### B14 — Trusted/peer cloud browse uses Tor not FIPS — ROOT-CAUSED (plan ready: record_peer_transport in 4 handlers; VERIFY actual transport)
+### B14 — cloud browse transport not recorded — FIXED (record_peer_transport in 4 content handlers; build OK). NOTE: live data shows FIPS reaches only ~4/15 peers, 6 fall back to Tor genuinely → see B14b.
 Browsing trusted/peer nodes in the Cloud tab connects over Tor instead of FIPS (should prefer FIPS like the rest of mesh; same for peer browsing). cf project_fips_integration, project_tor_node_to_node_works (last_transport should be fips/mesh).
 
 ---
@@ -105,6 +105,9 @@ When an update download fails, the UI sometimes shows the Install button instead
 ### B20 — Surface bitcoin-headers-over-mesh broadcast (send/receive toggles) — TODO (feature-adjacent, surfacing existing work)
 We previously broadcast bitcoin block headers over mesh to archipelago nodes but never fully surfaced it. Want two switches: "send headers" (you broadcast) and "receive headers" (you accept). NOTE: this is feature-adjacent — surfacing existing functionality; the user added it during the no-new-features push, so treat as low-priority polish until the bug list is clear. Code: mesh block-headers (mesh.block-headers RPC seen in logs; core/archipelago/src/mesh).
 
+### B14b — FIPS reachability: many peers fall back to Tor — TODO (priority, deeper)
+Live (2026-06-15) federation sync last_transport on .116/.198: ~4 peers fips, ~6 tor, ~5 none. So beyond the recording fix (B14), FIPS genuinely doesn't reach many federated peers (they use Tor). Investigate WHY: is fips_npub known for those peers? are they FIPS-online? is the shared anchor connecting them? (cf project_fips_integration, project_tor_node_to_node_works). This is the real "Tor not FIPS" depth.
+
 ### B8 — netbird app doesn't work — TODO  (LOW / much later)
 
 (RETRACTED: CryptPad placeholder-icon — user says cryptpad is fine.)