feat: add bsk network read-only command

Add `bsk network` as a sibling of the `console` command from #7,
reading the buffered network responses / failures for a tab. Fills the
remaining half of the request in #2 (console landed in #7; network did
not).

Mirrors the console command's conventions exactly:

  bsk network --session <id> [--tab-id N] [--since C]
                             [--limit N] [--max-text-chars N]

The extension enables `Network` on attach (best-effort) and buffers
`responseReceived` / `loadingFailed` events per tab with a monotonic
sequence, correlating them to `requestWillBeSent` for method/URL. Reads
are cursor-paginated (`since` -> `next_since`) and bounded (`limit`,
`max_text_chars`) for agent-context safety, same as console. Entries
carry the real HTTP status code (response) or the CDP failure reason
(failure) — things `performance.getEntriesByType('resource')` can't
give.

Classified read-only (pass-through under the pending-interrupt gate);
defaults to the Agent Window's active tab.

Wires bsk-protocol (Method + params/result/entry structs + schema),
bsk-cli (network subcommand + daemon dispatch allow-list) and the
extension (handler + dispatcher route), with unit / parse / IPC tests
paralleling the console command.

Refs #2.

crates/bsk-protocol/schema/tool_network_entry.json

@@ -0,0 +1,94 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "title": "NetworkEntry",
+  "type": "object",
+  "required": [
+    "kind",
+    "sequence",
+    "url"
+  ],
+  "properties": {
+    "error_text": {
+      "description": "CDP failure reason (`failure` entries only).",
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "kind": {
+      "$ref": "#/definitions/NetworkEntryKind"
+    },
+    "method": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "mime_type": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "resource_type": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "sequence": {
+      "type": "integer",
+      "format": "uint64",
+      "minimum": 0.0
+    },
+    "status": {
+      "description": "HTTP status code (`response` entries only).",
+      "type": [
+        "integer",
+        "null"
+      ],
+      "format": "uint32",
+      "minimum": 0.0
+    },
+    "status_text": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "timestamp": {
+      "type": [
+        "number",
+        "null"
+      ],
+      "format": "double"
+    },
+    "truncated": {
+      "default": false,
+      "type": "boolean"
+    },
+    "url": {
+      "type": "string"
+    }
+  },
+  "definitions": {
+    "NetworkEntryKind": {
+      "oneOf": [
+        {
+          "description": "A response was received (`Network.responseReceived`).",
+          "type": "string",
+          "enum": [
+            "response"
+          ]
+        },
+        {
+          "description": "The request failed before completing (`Network.loadingFailed`).",
+          "type": "string",
+          "enum": [
+            "failure"
+          ]
+        }
+      ]
+    }
+  }
+}