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/bfbc2.json

@@ -0,0 +1,53 @@
+{
+  "schema_version": 1,
+  "game_id": "bfbc2",
+  "game_version": "20210416",
+  "chunk_size": 134217728,
+  "files": [
+    {
+      "canonical_path": "bfbc2.eti",
+      "kind": "file",
+      "size": 3146114,
+      "file_blake3": "2e4022096dfd3114ec7bacf69c6c25bd83b9a6d3af71e81df4ba8584fc23a82b",
+      "chunk_blake3": [
+        "2e4022096dfd3114ec7bacf69c6c25bd83b9a6d3af71e81df4ba8584fc23a82b"
+      ]
+    },
+    {
+      "canonical_path": "version.ini",
+      "kind": "file",
+      "size": 8,
+      "file_blake3": "6eacd1c0e8efe8f809658ee66b9272d32daa1daadd904469ce5f7d128d23c9d5",
+      "chunk_blake3": [
+        "6eacd1c0e8efe8f809658ee66b9272d32daa1daadd904469ce5f7d128d23c9d5"
+      ]
+    }
+  ],
+  "streamed_install_files": [
+    {
+      "canonical_path": "bin",
+      "kind": "directory",
+      "size": 0,
+      "file_blake3": null
+    },
+    {
+      "canonical_path": "bin/bfbc2-payload.bin",
+      "kind": "file",
+      "size": 2097152,
+      "file_blake3": "4d6d0c9ee250f23e4828fd50872eecf945c022d0d82cc1a11bf25c96ef0ec807"
+    },
+    {
+      "canonical_path": "data",
+      "kind": "directory",
+      "size": 0,
+      "file_blake3": null
+    },
+    {
+      "canonical_path": "data/bfbc2-assets.dat",
+      "kind": "file",
+      "size": 1048576,
+      "file_blake3": "16daa7902e05888c38b984bac96bb5af496e43331bd3d8e858f019c8fd09dda5"
+    }
+  ],
+  "content_id": "ddd30de1727ec7bb37dad961217de619b514a71f47ccb4d7acbfcb8ad21f50d3"
+}