WTA ACP 0.10→1.0 migration

[DDKinger]

WTA ACP 0.10 → 1.0 migration (behavior-preserving)

Migrates the WTA helper/master ACP plane from agent-client-protocol 0.10 (the removed ClientSideConnection/AgentSideConnection trait-impl model) onto 1.0's builder/dispatch model. The migration itself is behavior-preserving; this PR also bundles the fixes that surfaced while doing it.

Migration

• Cargo: agent-client-protocol 0.10 → 1.0; dropped the now-stabilized unstable_session_list / unstable_session_model features. Regenerated cgmanifest.json + NOTICE.md. (No agent-client-protocol-tokio — it's stuck at 0.11.1 needing core ^0.11; Client/Agent/ByteStreams ship in core 1.0.)
• New conn.rs compat shim: re-exposes the old "stash a connection, drive I/O on the side, call typed methods later" shape on top of the 1.0 builder model — ClientLink / AgentLink / spawn_client / spawn_agent / byte_streams, each returning a handle_io liveness future. Re-declares the dropped session/set_model request locally so Copilot/Gemini model switching keeps working (Claude switches via the still-standard session/set_config_option).
• client.rs / master/mod.rs: ClientSideConnection / AgentSideConnection → Client / Agent.builder().on_receive_*().connect_with(...); conn.method().await → cx.send_request().block_task().await; the 5 impl acp::Client/Agent blocks → builder callbacks.
• ~538 mechanical acp::<T> → acp::schema::v1::<T> path moves.

Fixes bundled in

• Preserve the master-death degraded-state contract from fix(agent): consistent disconnected state when wta-master dies — recover with /restart, no split-brain #329 under ACP 1.0: killing wta-master must drop the pane out of Connected into the /restart-only state (no split-brain). The 1.0 rewrite regressed this — a clean pipe EOF no longer resolved handle_io — so the helper now watches the transport reader directly (DeathWatchRead → TransportDeath) to restore it.
• Model-switch fallback: on the config-option channel, a MethodNotFound from session/set_config_option now falls back to legacy session/set_model (and records Legacy), so an agent that advertises a config-option model selector but only implements set_model still switches. Before schema 1.1 dropped NewSessionResponse.models, the legacy field took priority and this couldn't arise.
• Shared agent-CLI deadlock: a reentrant request_permission mid-prompt no longer wedges the master dispatch loop — 1.0 dispatches handlers serially inline, so the handler is now spawned instead of inline-awaited.
• ACP 1.0 ext methods: account for the leading-underscore strip 1.0 applies on receive, so the _intellterm.wta/* local methods are matched instead of falling through to the agent CLI.
• Connection-setup failure surfaces as an error instead of a busy-wait spin, and callers no longer risk spinning until an external timeout.
• Delegate to a non-launchable agent now opens a persistent single-line error tab instead of a tab that flashes shut before the user can read the error.

Tests

• New unit guards for TransportDeath / DeathWatchRead and for handle_io resolving on peer death (both client and agent sides).
• Model-switch fallback tests: config-option MethodNotFound falls back to set_model and flips the channel to Legacy; a non-MethodNotFound error propagates without falling back.
• Hardened SessionList e2e against the arrow-key re-render race and made draft-preservation view detection read pane text rather than a UIA label.
• Full WTA unit suite: 998 pass / 0 fail; cargo build clean.

[github-advanced-security]

check-spelling found more than 20 potential problems in the proposed changes. Check the Files changed tab for more details.

[Copilot]

Pull request overview

This PR performs Phase 0 of the WTA ACP 0.10 → 1.0 migration by updating the WTA helper/master ACP plumbing to the agent-client-protocol 1.0 builder/dispatch model while aiming to preserve existing behavior. It also adds a compat layer (protocol::acp::conn) to keep the rest of the WTA code using a “connection handle + handle_io future” shape similar to the pre-1.0 API.

Changes:

• Upgrades agent-client-protocol to 1.0 and rewrites ACP message/type usage to acp::schema::v1::*.
• Introduces tools/wta/src/protocol/acp/conn.rs as a compatibility shim around 1.0 ConnectionTo<>, and migrates helper/probe/CLI/test paths to use it.
• Regenerates third-party notices (cgmanifest.json, NOTICE.md) and adds a new migration design spec.

Reviewed changes

Copilot reviewed 19 out of 20 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tools/wta/src/shell/wt_channel/mod.rs	Adjusts public re-exports for wtcli channel helpers.
tools/wta/src/protocol/acp/soft_stop.rs	Updates stop-reason typing to acp::schema::v1 and aligns tests.
tools/wta/src/protocol/acp/probe.rs	Migrates probe-models ACP path to the 1.0 connection shim and v1 schema types.
tools/wta/src/protocol/acp/model_select.rs	Reworks model extraction/switching to schema v1 config-options + legacy set-model compatibility path.
tools/wta/src/protocol/acp/mod.rs	Exposes the new conn module in the ACP protocol tree.
tools/wta/src/protocol/acp/mock_agent_tests.rs	Updates in-process ACP mock harness to builder/dispatch model using the connection shim.
tools/wta/src/protocol/acp/conn.rs	Adds a 1.0 “compat shim” (ClientLink/AgentLink, spawn helpers, and legacy session/set_model request).
tools/wta/src/protocol/acp/client.rs	Migrates helper ACP client wiring and dispatcher to builder/dispatch and the connection shim.
tools/wta/src/main.rs	Updates CLI entrypoints (probe-models, sessions list, delegate registration) to use builder/dispatch + LocalSet + shim.
tools/wta/src/cli_tests.rs	Updates tests for schema v1 SessionId path changes.
tools/wta/src/app.rs	Updates app state/event types and ACP call sites to schema v1 ids and requests.
tools/wta/src/agent_hooks_installer.rs	Minor signature cleanup to silence unused parameter warnings.
tools/wta/src/agent_check.rs	Removes now-unused imports.
tools/wta/cgmanifest.json	Updates CG manifest entries for the new ACP crate versions (and new derive crate).
tools/wta/Cargo.toml	Bumps agent-client-protocol dependency to 1.0 and drops unstable feature flags.
tools/wta/Cargo.lock	Updates lockfile to ACP 1.0 dependency graph and new transitive crates.
NOTICE.md	Regenerates third-party attributions to match the updated Rust dependency graph.
doc/specs/acp-1.0-conductor-migration.md	Adds a detailed spec/plan for the broader conductor/proxy migration beyond Phase 0.

Comments suppressed due to low confidence (1)

tools/wta/src/protocol/acp/model_select.rs:63

• models_from_new_session no longer updates MODEL_SWITCH when the agent does not advertise a model selector in config_options. Because MODEL_SWITCH is process-global, this can leave a stale Config { config_id } from a previous session and later route apply_session_model to session/set_config_option with the wrong config_id (or when the agent only supports legacy switching). The doc comment above the function also still claims we prefer the legacy models field, but the schema 1.1 type no longer exposes it.

Reset the channel to Legacy when no config-option model selector is found, and update the doc comment to match the new behavior.

/// Extract the model list and current model id from a `new_session` response,
/// preferring the legacy `models` field and falling back to a `config_options`
/// `Select` with `category == Model`. Records the switch channel as a side
/// effect so [`apply_session_model`] later dispatches correctly.
pub(crate) fn models_from_new_session(
    resp: &acp::schema::v1::NewSessionResponse,
) -> (Vec<AcpModelInfo>, Option<String>) {
    if let Some(opts) = &resp.config_options {
        if let Some((config_id, models, current)) = model_option_from_config(opts) {
            record_channel_config(&config_id);
            return (models, current);
        }
    }

    (Vec::new(), None)
}

[Copilot]

Pull request overview

Copilot reviewed 23 out of 24 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

tools/wta/src/protocol/acp/model_select.rs:59

• models_from_new_session only records the switch channel when a model config_options entry is found, which can leave a stale ModelSwitchChannel::Config value across agent restarts or across new_session responses that don't carry the model selector. This contradicts the module comment that the channel is refreshed on every parse, and can cause apply_session_model to send session/set_config_option to an agent that only supports legacy session/set_model. Reset the channel to Legacy at the start of each parse, then override to Config when a model selector is found.

    if let Some(opts) = &resp.config_options {
        if let Some((config_id, models, current)) = model_option_from_config(opts) {
            record_channel_config(&config_id);
            return (models, current);
        }

[Copilot]

Pull request overview

Copilot reviewed 23 out of 24 changed files in this pull request and generated 3 comments.

Comments suppressed due to low confidence (1)

tools/wta/src/protocol/acp/model_select.rs:59

• models_from_new_session only records the switch channel when a model config option is present. If it previously saw a config-option model selector, then later parses a new_session response with no model config option, MODEL_SWITCH remains stuck in Config, and apply_session_model will incorrectly try session/set_config_option against legacy agents (Copilot/Gemini), causing model switching to fail. Reset the channel back to Legacy when no model option is parsed so the channel is refreshed on every parse as the module docs describe.

    if let Some(opts) = &resp.config_options {
        if let Some((config_id, models, current)) = model_option_from_config(opts) {
            record_channel_config(&config_id);
            return (models, current);
        }

[Copilot]

Pull request overview

Copilot reviewed 25 out of 26 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 25 out of 26 changed files in this pull request and generated 1 comment.