feat(v0.6.1): file_reread signal — catch offset-shifted same-file re-reads

Proposed and approved through ADAM's own /reflect harness_edit loop (MOSS §1):
the analyst surfaced 23 tool_error_loop entries across 4 sessions whose context
windows were really redundant re-reads of one file.

retry_loop keys on argsHash of the full tool_input (including offset/limit), so
consecutive Reads of the SAME file at different offsets escaped dedup and leaked
into tool_error_loop fingerprints. The new file_reread signal catches them:
same file Read >=3x in the 10-event window, offset-agnostic (keyed on file
path), guarded by `sameToolArgs < RETRY_THRESHOLD` so byte-identical reads stay
with retry_loop (no double-count).

Fully wired end-to-end (not a half-dead signal):
- adam-observe.mjs: detection + STRUGGLE_TYPES membership (so it carries
  context_window + active_skills like other struggle signals).
- adam-window.mjs: 14-day sliding window (task-local, like retry_loop).
- adam-score.mjs: severity divisor 3.
- adam-batch.mjs: file-basename clustering.
- agents/adam.md + README: signal tables, clustering rules, rubric, windows.

Tests: 126 -> 132 (file_reread fires on 3x offset-shifted reads, not on 2x;
byte-identical reads route to retry_loop not file_reread; carries context_window).

hooks/adam-observe.mjs

@@ -105,11 +105,13 @@ const SUBAGENT_DISPATCH_THRESHOLD = 3;
 const CORRECTION_FREE_THRESHOLD = 5;
 const CLEAN_RECOVERY_WINDOW = 3;
 const SILENT_DRIFT_THRESHOLD = 5;
+const FILE_REREAD_THRESHOLD = 3;
 const ERROR_AFTER_RECOVERY_WINDOW = 5;
 const RECENT_RECOVERIES_MAX = 3;
 const STRUGGLE_TYPES = new Set([
   "tool_error_loop", "dead_end", "retry_loop", "weak_agent",
   "edit_churn", "build_loop", "silent_drift", "error_after_recovery",
+  "file_reread",
 ]);
 const ACTIVE_SKILLS_LOOKBACK = 10;
 const TASK_TOOL_MIN = 5;
@@ -470,6 +472,16 @@ function main() {
       emit({ ts, session, cwd, type: "retry_loop", tool, count: sameToolArgs });
     }
 
+    // Offset-aware same-file reread: consecutive Reads of the same file_path
+    // (ignoring offset/limit) escape the argsHash-based retry_loop dedup above.
+    // Emit a distinct, actionable signal instead of leaking into tool_error_loop.
+    if (READ_ONLY_TOOLS.has(tool) && file) {
+      const sameFileReads = state.tool_window.filter(e => e.tool === tool && e.file === file).length;
+      if (sameFileReads >= FILE_REREAD_THRESHOLD && sameToolArgs < RETRY_THRESHOLD) {
+        emit({ ts, session, cwd, type: "file_reread", tool, file, count: sameFileReads });
+      }
+    }
+
     if (READ_ONLY_TOOLS.has(tool)) {
       state.silentDriftCounter += 1;
       if (state.silentDriftCounter >= SILENT_DRIFT_THRESHOLD && !state.silentDriftEmitted) {