fix(failures): use is_error field instead of content pattern matching

Index the is_error boolean from JSONL tool_result blocks into a new
  column, replacing the old ERROR_PATS text-matching approach that
  produced ~90% false positives. Bash exit code pattern kept as fallback.

scripts/db.mjs

@@ -24,7 +24,7 @@ CREATE TABLE IF NOT EXISTS tool_calls (
   name TEXT, input_json TEXT, file_path TEXT);
 CREATE TABLE IF NOT EXISTS tool_results (
   tool_use_id TEXT PRIMARY KEY, message_uuid TEXT, session_id TEXT,
-  content TEXT, file_path TEXT);
+  content TEXT, file_path TEXT, is_error INTEGER DEFAULT 0);
 CREATE TABLE IF NOT EXISTS subagents (
   agent_id TEXT PRIMARY KEY, session_id TEXT, parent_tool_use_id TEXT,
   agent_type TEXT, description TEXT, duration_ms INTEGER, total_tokens INTEGER);

scripts/indexer.mjs

@@ -61,7 +61,7 @@ function indexJsonl(db, fi) {
     ses: db.prepare('INSERT OR REPLACE INTO sessions (id,title,project,project_path,started_at,ended_at,git_branch,version,message_count,jsonl_path) VALUES (?,?,?,?,?,?,?,?,?,?)'),
     msg: db.prepare('INSERT OR REPLACE INTO messages (uuid,session_id,type,parent_uuid,timestamp,role,text,model,is_sidechain,agent_id,input_tokens,output_tokens) VALUES (?,?,?,?,?,?,?,?,?,?,?,?)'),
     tc:  db.prepare('INSERT OR REPLACE INTO tool_calls (id,message_uuid,session_id,name,input_json,file_path) VALUES (?,?,?,?,?,?)'),
-    tr:  db.prepare('INSERT OR REPLACE INTO tool_results (tool_use_id,message_uuid,session_id,content,file_path) VALUES (?,?,?,?,?)'),
+    tr:  db.prepare('INSERT OR REPLACE INTO tool_results (tool_use_id,message_uuid,session_id,content,file_path,is_error) VALUES (?,?,?,?,?,?)'),
     sum: db.prepare('INSERT OR REPLACE INTO summaries (id,session_id,timestamp,source,content) VALUES (?,?,?,?,?)'),
     idx: db.prepare('INSERT OR REPLACE INTO index_state (jsonl_path,mtime,lines_processed) VALUES (?,?,?)'),
   };
@@ -121,7 +121,7 @@ function indexJsonl(db, fi) {
         if (b.type !== 'tool_result' || !b.tool_use_id) continue;
         const rt = typeof b.content === 'string' ? b.content
           : Array.isArray(b.content) ? b.content.map(c => c.text || '').join('\n') : '';
-        ins.tr.run(b.tool_use_id, obj.uuid, sid, trunc(rt), obj.toolUseResult?.filePath || null);
+        ins.tr.run(b.tool_use_id, obj.uuid, sid, trunc(rt), obj.toolUseResult?.filePath || null, b.is_error ? 1 : 0);
       }
     }
   });

scripts/query.mjs

@@ -1,7 +1,5 @@
 import { openDb, readLines, fs, path } from './db.mjs';
 
-const ERROR_PATS = ['error','Error','ENOENT','failed','Failed','FAILED','permission denied','Permission denied','EPERM','EACCES','command not found','No such file','Exit code'];
-
 function normalizeOpts(optsOrScalar, scalarKey = 'sessionId') {
   if (optsOrScalar == null) return {};
   if (typeof optsOrScalar === 'string') return { [scalarKey]: optsOrScalar };
@@ -24,6 +22,8 @@ function buildWhere(opts, aliases) {
   return { where: clauses.length ? clauses.join(' AND ') : '1=1', params };
 }
 
+const BASH_EXIT_PAT = 'Exit code [1-9]%';
+
 function createQueryApi(db) {
   const q = (sql, ...p) => db.prepare(sql).all(...p);
 
@@ -129,13 +129,12 @@ function createQueryApi(db) {
   const failures = (optsOrSid) => {
     const opts = normalizeOpts(optsOrSid);
     const { limit = 50 } = opts;
-    const likeClauses = ERROR_PATS.map(() => 'tr.content LIKE ?').join(' OR ');
-    const likeParams = ERROR_PATS.map(p => `%${p}%`);
     const needsJoin = opts.project || opts.branch;
     const { where, params: filterParams } = buildWhere(opts, { sessionId: 'tr.session_id', project: 's.project', timestamp: 'rm.timestamp', branch: 's.git_branch' });
     const join = needsJoin ? 'LEFT JOIN sessions s ON s.id=tr.session_id' : '';
-    const allParams = [...likeParams, ...filterParams, limit];
-    const rows = db.prepare(`SELECT tr.* FROM tool_results tr ${join} LEFT JOIN messages rm ON rm.uuid=tr.message_uuid WHERE (${likeClauses}) AND ${where} LIMIT ?`).all(...allParams);
+    const errorCond = `(tr.is_error = 1 OR tr.content LIKE '${BASH_EXIT_PAT}')`;
+    const allParams = [...filterParams, limit];
+    const rows = db.prepare(`SELECT tr.* FROM tool_results tr ${join} LEFT JOIN messages rm ON rm.uuid=tr.message_uuid WHERE ${errorCond} AND ${where} LIMIT ?`).all(...allParams);
     return rows.map(r => {
       const tc = db.prepare('SELECT * FROM tool_calls WHERE id=?').get(r.tool_use_id);
       const session = db.prepare('SELECT * FROM sessions WHERE id=?').get(r.session_id);