huskies: merge 686_refactor_decompose_server_src_io_watcher_rs_1202_lines

Manual merge resolution: feature branch deleted watcher.rs and split
into watcher/{mod,events,sweep,tests}.rs, while master modified the
old watcher.rs (738's FS-shadow stripping). The auto-resolver kept
both, producing an ambiguous-module compile error.

Resolution: drop watcher.rs (feature's delete wins). The new
watcher/mod.rs absorbs the FS-shadow code semantically — gates pass
(cargo check, clippy --all-targets -D warnings, fmt --check, 29/29
io::watcher tests).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/src/io/watcher/events.rs

@@ -0,0 +1,75 @@
+//! Watcher event types emitted to WebSocket clients and internal subscribers.
+
+use serde::Serialize;
+
+/// A lifecycle event emitted by the filesystem watcher.
+#[derive(Clone, Debug, Serialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum WatcherEvent {
+    /// A work-pipeline file was created, modified, or deleted.
+    WorkItem {
+        /// Pipeline stage directory (e.g. `"2_current"`, `"5_archived"`).
+        stage: String,
+        /// Work item ID (filename stem without extension, e.g. `"42_story_my_feature"`).
+        item_id: String,
+        /// Semantic action inferred from the stage (e.g. `"start"`, `"accept"`).
+        action: String,
+        /// The deterministic git commit message used (or that would have been used).
+        commit_msg: String,
+        /// The pipeline stage the item moved FROM, populated for move operations.
+        /// `None` for creations, deletions, or synthetic events.
+        from_stage: Option<String>,
+    },
+    /// `.huskies/project.toml` was modified at the project root (not inside a worktree).
+    ConfigChanged,
+    /// An agent's state changed (started, stopped, completed, etc.).
+    /// Triggers a pipeline state refresh so the frontend can update agent
+    /// assignments without waiting for a filesystem event.
+    AgentStateChanged,
+    /// A story encountered a failure (e.g. merge failure).
+    /// Triggers an error notification to configured Matrix rooms.
+    MergeFailure {
+        /// Work item ID (e.g. `"42_story_my_feature"`).
+        story_id: String,
+        /// Human-readable description of the failure.
+        reason: String,
+    },
+    /// An agent hit an API rate limit.
+    /// Triggers a warning notification to configured chat rooms.
+    RateLimitWarning {
+        /// Work item ID the agent is working on.
+        story_id: String,
+        /// Name of the agent that hit the rate limit.
+        agent_name: String,
+    },
+    /// A story has been blocked (e.g. retry limit exceeded, empty diff).
+    /// Triggers a warning notification to configured chat rooms.
+    StoryBlocked {
+        /// Work item ID (e.g. `"42_story_my_feature"`).
+        story_id: String,
+        /// Human-readable reason the story was blocked.
+        reason: String,
+    },
+    /// An agent hit a hard API rate limit and will be blocked until `reset_at`.
+    /// Triggers auto-scheduling of a timer and a notification with the resume time.
+    RateLimitHardBlock {
+        /// Work item ID the agent is working on.
+        story_id: String,
+        /// Name of the agent that hit the hard rate limit.
+        agent_name: String,
+        /// UTC instant at which the rate limit resets.
+        reset_at: chrono::DateTime<chrono::Utc>,
+    },
+    /// An OAuth account pool swap succeeded: a different account is now active.
+    /// Triggers a notification to chat transports naming the new account.
+    OAuthAccountSwapped {
+        /// Email address of the newly activated account.
+        new_email: String,
+    },
+    /// All OAuth accounts in the pool are rate-limited — no swap was possible.
+    /// Triggers a notification to chat transports with the earliest reset time.
+    OAuthAccountsExhausted {
+        /// Human-readable message describing when the earliest reset occurs.
+        earliest_reset_msg: String,
+    },
+}