feat(peer)!: cut over to authenticated catalog sharing

Replace address-only trust and pushed peer state with installation identities,
SPKI-pinned QUIC, candidate-only discovery, and bounded responder-owned
protocol-8 pulls. The runtime now owns each network generation and all admitted
work through shutdown.

Add exact bundled content identities, reproducible manifest publishing,
capability-confined downloads, streaming BLAKE3 verification, quarantine and
retry, and crash-recoverable download and install transactions. Ship generated
fixture catalogs and fail closed when production manifests are absent.

The Tauri backend exposes durable sharing policy, redacted identity state, and
attempt-keyed transfer snapshots. Frontend consumption follows in the next
commit. Repository-wide test certificates and protocol-7 paths are removed.

BREAKING CHANGE: peers must use protocol 8 and exact catalog content artifacts;
protocol-7 frames and shared-certificate identities are no longer accepted.

Test Plan:
- `just test` -- passed on the completed stack (708 workspace tests)
- `just clippy` -- passed on the completed stack
- `just build` -- passed with fixture catalogs on the completed stack
- `just catalog-check-production` -- failed closed because the external
  production manifest corpus is absent
- `git diff --cached --check` -- passed

crates/lanspread-peer-cli/catalogs/default/manifests/coh.json

@@ -0,0 +1,53 @@
+{
+  "schema_version": 1,
+  "game_id": "coh",
+  "game_version": "20200907",
+  "chunk_size": 134217728,
+  "files": [
+    {
+      "canonical_path": "coh.eti",
+      "kind": "file",
+      "size": 3146106,
+      "file_blake3": "51c8a7d80b2424c262f55beabbc26b31a878ab3b5df7b8470b1f5838d02fa214",
+      "chunk_blake3": [
+        "51c8a7d80b2424c262f55beabbc26b31a878ab3b5df7b8470b1f5838d02fa214"
+      ]
+    },
+    {
+      "canonical_path": "version.ini",
+      "kind": "file",
+      "size": 8,
+      "file_blake3": "5f033915cb29613e39a19fba14b466689a996a621c8b3e3f1f3bd133bed9a50a",
+      "chunk_blake3": [
+        "5f033915cb29613e39a19fba14b466689a996a621c8b3e3f1f3bd133bed9a50a"
+      ]
+    }
+  ],
+  "streamed_install_files": [
+    {
+      "canonical_path": "bin",
+      "kind": "directory",
+      "size": 0,
+      "file_blake3": null
+    },
+    {
+      "canonical_path": "bin/coh-payload.bin",
+      "kind": "file",
+      "size": 2097152,
+      "file_blake3": "cf081a2e71ae96aa1505605e75ae3651dfc59e395e7fcfd5f5520fa1eb133fb3"
+    },
+    {
+      "canonical_path": "data",
+      "kind": "directory",
+      "size": 0,
+      "file_blake3": null
+    },
+    {
+      "canonical_path": "data/coh-assets.dat",
+      "kind": "file",
+      "size": 1048576,
+      "file_blake3": "ac5eadb10f22a57f9072c19d141212cdb847fee759f38af31c5a96a6ff80d748"
+    }
+  ],
+  "content_id": "7cf80604d1811b8683c415a60415a6e980bb25e42146b4b474324d47e068f34d"
+}