refactor: extract AppEvent to crates/ironclaw_common (#1615)

* refactor: extract AppEvent to crates/ironclaw_common

SseEvent was defined in src/channels/web/types.rs but imported by 12+
modules across agent, orchestrator, worker, tools, and extensions — it
had become the application-wide event protocol, not a web transport
concern.

Create crates/ironclaw_common as a shared workspace crate and move the
enum there as AppEvent.  Also move the truncate_preview utility which
was similarly leaked from the web gateway into agent modules.

- New crate: crates/ironclaw_common (AppEvent, truncate_preview)
- Rename SseEvent → AppEvent, from_sse_event → from_app_event
- web/types.rs re-exports AppEvent for internal gateway use
- web/util.rs re-exports truncate_preview
- Wire format unchanged (serde renames are on variants, not the enum)

Aligned with the event bus direction on refactor/architectural-hardening
where DomainEvent (≡ AppEvent) is wrapped in a SystemEvent envelope.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* refactor: add AppEvent::event_type() helper, deduplicate match blocks

Address Gemini review: extract the variant→string match into a single
method on AppEvent, replacing the duplicated 22-arm matches in sse.rs
and types.rs.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* refactor: rename leftover sse vars/tests to match AppEvent rename

Address Copilot review: rename sse_event vars to app_event in
orchestrator/api.rs and ws.rs, rename test functions from
test_ws_server_from_sse_* to test_ws_server_from_app_event_*, and
update stale SSE comments.

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

* refactor: add Deserialize to AppEvent, round-trip test, fix stale comments

Address zmanian review:
- Add Deserialize derive to AppEvent so downstream consumers can
  deserialize incoming events
- Add event_type_matches_serde_type_field test that round-trips every
  variant through serde and asserts event_type() matches the serialized
  "type" field — catches drift between serde renames and the manual match
- Add round_trip_deserialize test for basic Serialize/Deserialize parity
- Update remaining "SSE" references in comments across server.rs,
  manager.rs, ws_gateway_integration.rs, and worker/job.rs

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>

src/tools/builtin/job.rs

@@ -17,7 +17,6 @@ use uuid::Uuid;
 
 use crate::bootstrap::ironclaw_base_dir;
 use crate::channels::IncomingMessage;
-use crate::channels::web::types::SseEvent;
 use crate::context::{ContextManager, JobContext, JobState};
 use crate::db::Database;
 use crate::history::SandboxJobRecord;
@@ -25,6 +24,7 @@ use crate::orchestrator::auth::CredentialGrant;
 use crate::orchestrator::job_manager::{ContainerJobManager, JobMode};
 use crate::secrets::SecretsStore;
 use crate::tools::tool::{ApprovalRequirement, Tool, ToolError, ToolOutput, require_str};
+use ironclaw_common::AppEvent;
 
 /// Lazy scheduler reference, filled after Agent::new creates the Scheduler.
 ///
@@ -85,7 +85,7 @@ pub struct CreateJobTool {
     job_manager: Option<Arc<ContainerJobManager>>,
     store: Option<Arc<dyn Database>>,
     /// Broadcast sender for job events (used to subscribe a monitor).
-    event_tx: Option<tokio::sync::broadcast::Sender<(Uuid, String, SseEvent)>>,
+    event_tx: Option<tokio::sync::broadcast::Sender<(Uuid, String, AppEvent)>>,
     /// Injection channel for pushing messages into the agent loop.
     inject_tx: Option<tokio::sync::mpsc::Sender<IncomingMessage>>,
     /// Encrypted secrets store for validating credential grants.
@@ -120,7 +120,7 @@ impl CreateJobTool {
     /// monitor that forwards Claude Code output to the main agent loop.
     pub fn with_monitor_deps(
         mut self,
-        event_tx: tokio::sync::broadcast::Sender<(Uuid, String, SseEvent)>,
+        event_tx: tokio::sync::broadcast::Sender<(Uuid, String, AppEvent)>,
         inject_tx: tokio::sync::mpsc::Sender<IncomingMessage>,
     ) -> Self {
         self.event_tx = Some(event_tx);

src/tools/registry.rs

@@ -383,11 +383,7 @@ impl ToolRegistry {
         job_manager: Option<Arc<ContainerJobManager>>,
         store: Option<Arc<dyn Database>>,
         job_event_tx: Option<
-            tokio::sync::broadcast::Sender<(
-                uuid::Uuid,
-                String,
-                crate::channels::web::types::SseEvent,
-            )>,
+            tokio::sync::broadcast::Sender<(uuid::Uuid, String, ironclaw_common::AppEvent)>,
         >,
         inject_tx: Option<tokio::sync::mpsc::Sender<crate::channels::IncomingMessage>>,
         prompt_queue: Option<PromptQueue>,