feat: Wave 1 complete — state machine, Paseo hub, collision detection, PTY search

- Task state machine: TIMED_OUT state, retriable steps, timeout detection
- Paseo hub: paseo-client.ts (HTTP+CLI), PaseoBackend (AgentBackend), 14 tests
- Collision detection: collision-detector.ts, conflict-index.ts, ws-frames type
- PTY search: ring buffer, search route, capture-pane fallback

apps/coder/src/services/conflict-index.ts

@@ -0,0 +1,151 @@
+// v2.8 In-memory conflict index — tracks which worktrees/agents are editing
+// which files so the collision detector can find overlaps.
+//
+// Singleton exported as `conflictIndex`; imported by pending_changes.ts to
+// register changes at queue time and unregister on worktree teardown.
+//
+// NOT persisted — survives only as long as the BooCoder process. Postgres
+// is the durable record (pending_changes table); this is the hot in-memory
+// probe for concurrent edit warnings.
+
+import type { ConflictEntry, ConflictVerdict } from './collision-detector.js';
+import { findConflicts } from './collision-detector.js';
+
+export class ConflictIndex {
+  /**
+   * filePath → Set of ConflictEntry from various worktrees.
+   * A single worktree may have multiple entries for the same file
+   * (several pending edits to the same file in one session).
+   */
+  #map = new Map<string, Set<ConflictEntry>>();
+
+  // ---- mutation -------------------------------------------------------
+
+  /**
+   * Register that `worktreeId` (agent) is touching `filePath`.
+   * Creates an entry in the index so subsequent callers see it as a conflict.
+   */
+  registerChange(
+    filePath: string,
+    worktreeId: string,
+    agent: string,
+    lineRange?: { start: number; end: number },
+  ): void {
+    let entries = this.#map.get(filePath);
+    if (!entries) {
+      entries = new Set();
+      this.#map.set(filePath, entries);
+    }
+    entries.add({
+      worktreeId,
+      agent,
+      lineRange,
+      status: 'pending' as const,
+      timestamp: Date.now(),
+    });
+  }
+
+  /**
+   * Remove all entries for a given worktree. Called on worktree teardown
+   * so stale entries don't trigger false warnings.
+   */
+  removeWorktree(worktreeId: string): void {
+    for (const [filePath, entries] of this.#map) {
+      const before = entries.size;
+      for (const entry of entries) {
+        if (entry.worktreeId === worktreeId) {
+          entries.delete(entry);
+        }
+      }
+      if (entries.size === 0) {
+        this.#map.delete(filePath);
+      }
+    }
+  }
+
+  /**
+   * Remove entries older than `maxAgeMs`. Useful as a periodic cleanup
+   * when worktree teardown was missed (crash, unclean exit).
+   */
+  sweepStale(maxAgeMs: number): number {
+    const cutoff = Date.now() - maxAgeMs;
+    let removed = 0;
+
+    for (const [filePath, entries] of this.#map) {
+      for (const entry of entries) {
+        if (entry.timestamp < cutoff) {
+          entries.delete(entry);
+          removed++;
+        }
+      }
+      if (entries.size === 0) {
+        this.#map.delete(filePath);
+      }
+    }
+
+    return removed;
+  }
+
+  // ---- query ----------------------------------------------------------
+
+  /**
+   * Query the raw ConflictEntry set for a file path. Returns empty set
+   * when there are no entries (never mutated the file).
+   */
+  getEntriesFor(filePath: string): ReadonlySet<ConflictEntry> {
+    return this.#map.get(filePath) ?? new Set();
+  }
+
+  /**
+   * Get all conflict verdicts for a given file path — which other
+   * worktrees are touching it. Returns empty when only one worktree
+   * has entries (no actual conflict).
+   */
+  getConflictsFor(filePath: string): ConflictVerdict[] {
+    const entries = this.#map.get(filePath);
+    if (!entries || entries.size === 0) return [];
+
+    // Determine distinct worktree IDs. If only one, no conflict.
+    const worktreeIds = new Set<string>();
+    for (const e of entries) worktreeIds.add(e.worktreeId);
+    if (worktreeIds.size <= 1) return [];
+
+    // Use the first worktree as the "caller" so findConflicts excludes
+    // its entries and returns only entries from OTHER worktrees.
+    const caller = [...worktreeIds][0]!;
+    return findConflicts(
+      [filePath],
+      caller,
+      new Map(),
+      this.#toIndexData(),
+    );
+  }
+
+  /**
+   * Get conflicts for a set of file changes from a specific worktree.
+   * Delegates to the pure findConflicts function.
+   */
+  query(
+    changedFiles: string[],
+    worktreeId: string,
+    changedRanges: Map<string, { start: number; end: number }>,
+  ): ConflictVerdict[] {
+    return findConflicts(changedFiles, worktreeId, changedRanges, this.#toIndexData());
+  }
+
+  /**
+   * Snapshot the current map for testing/inspection.
+   */
+  snapshot(): Map<string, ReadonlySet<ConflictEntry>> {
+    return new Map(this.#map);
+  }
+
+  // ---- private --------------------------------------------------------
+
+  #toIndexData(): ReadonlyMap<string, ReadonlySet<ConflictEntry>> {
+    return this.#map as ReadonlyMap<string, ReadonlySet<ConflictEntry>>;
+  }
+}
+
+// Singleton — the whole BooCoder process shares one conflict index.
+export const conflictIndex = new ConflictIndex();