Tauri plugin: commands missing from build.rs have no permission (start_transport_events, session_accept, try_next_chunk)

[momics]

Summary

Three Tauri commands are wired into the plugin's tauri::generate_handler![...] but are missing from the build.rs command list, so Tauri never generates an allow-* permission for them. They cannot be granted by any capability and fail at runtime with:

iroh-http.start_transport_events not allowed. Command not found

Affected commands:

Command	Breaks
start_transport_events	All transport / path-change observability (fires on every createNode)
session_accept	Accepting incoming QUIC sessions (server side of iroh-http:connect)
try_next_chunk	Fast-path body reads used by fetch and serve streaming

Evidence

packages/iroh-http-tauri/src/lib.rs registers all three in invoke_handler, but packages/iroh-http-tauri/build.rs Builder::new(&[...]) omits them. Tauri's permission generation is driven by build.rs, so no allow-start-transport-events, allow-try-next-chunk permission existed, and allow-session-accept only resolved via a stale autogenerated file (a clean rebuild would have removed it).

Additionally, even once generated, try_next_chunk and start_transport_events were not referenced by any permission set, so a capability could not enable them.

Impact

• node observability (path changes / diagnostics) is dead in the Tauri plugin — every createNode() logs start_transport_events not allowed. Command not found.
• Incoming session acceptance is fragile (works only by stale-file accident).
• Fast-path body streaming is unreachable.

This is the same "ACL drift invisible to the build" class as #246 (permission sets declared as [[permission]]). The build stays green because Tauri fails open / silently, and no test exercised command↔permission parity.

Remediation

1. Add try_next_chunk, session_accept, start_transport_events to build.rs so leaf permissions are generated.
2. Add allow-try-next-chunk to the fetch and serve sets; add allow-start-transport-events to [default] (it fires on createNode). allow-session-accept is already in the connect set.
3. Regenerate permissions/autogenerated/ and permissions/schemas/schema.json.
4. Add a regression guard (extends tests/permissions.rs) asserting parity between generate_handler!, build.rs, and the permission sets — so a registered command without a generated, granted permission fails CI.

Acceptance criteria

• generate_handler!, build.rs, and the permission sets list the identical command set (asserted by a test).
• Every generated command is granted by a [[set]] or [default] (asserted by a test).
• Enabling transport events / accepting sessions / fast-path body reads no longer fails with "Command not found".
• cargo test -p tauri-plugin-iroh-http --test permissions passes; cargo clippy -- -D warnings clean.