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/src/tools/mod.rs

@@ -5,6 +5,7 @@ pub mod dialog;
 pub mod human_loop;
 pub mod interaction;
 pub mod navigation;
+pub mod network;
 pub mod observation;
 pub mod script;
 pub mod session;
@@ -16,6 +17,7 @@ pub use dialog::*;
 pub use human_loop::*;
 pub use interaction::*;
 pub use navigation::*;
+pub use network::*;
 pub use observation::*;
 pub use script::*;
 pub use session::*;