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/cod6.json

@@ -0,0 +1,53 @@
+{
+  "schema_version": 1,
+  "game_id": "cod6",
+  "game_version": "20200315",
+  "chunk_size": 134217728,
+  "files": [
+    {
+      "canonical_path": "cod6.eti",
+      "kind": "file",
+      "size": 3146110,
+      "file_blake3": "ce096cadb67834be368fa1fe2141426810591a0febe6c4e960d729a4a436d30f",
+      "chunk_blake3": [
+        "ce096cadb67834be368fa1fe2141426810591a0febe6c4e960d729a4a436d30f"
+      ]
+    },
+    {
+      "canonical_path": "version.ini",
+      "kind": "file",
+      "size": 8,
+      "file_blake3": "fb541cd98ca1ce773b04cd44d27f182830ee5e04e63f0a268486826f5b33c424",
+      "chunk_blake3": [
+        "fb541cd98ca1ce773b04cd44d27f182830ee5e04e63f0a268486826f5b33c424"
+      ]
+    }
+  ],
+  "streamed_install_files": [
+    {
+      "canonical_path": "bin",
+      "kind": "directory",
+      "size": 0,
+      "file_blake3": null
+    },
+    {
+      "canonical_path": "bin/cod6-payload.bin",
+      "kind": "file",
+      "size": 2097152,
+      "file_blake3": "491b9181f503d31917709d5429e1f52686d52bf13562faedbc84031885aeca13"
+    },
+    {
+      "canonical_path": "data",
+      "kind": "directory",
+      "size": 0,
+      "file_blake3": null
+    },
+    {
+      "canonical_path": "data/cod6-assets.dat",
+      "kind": "file",
+      "size": 1048576,
+      "file_blake3": "ac874e3ac3438dee4c2e42165ead2fb9f84210760d1645294e4eed8ec6792cf4"
+    }
+  ],
+  "content_id": "dc2cfa0e4da3fdc7138dc37930a8503ead08883faa0f56f59598489b48de3153"
+}