fix: strip <system-reminder> tags from persisted memory and DRY up regex

System reminders (CLAUDE.md contents, deferred tool lists) were being
stored in memory observations. Add system-reminder to the tag stripping
pipeline alongside <private> and <system_instruction>, and extract the
duplicated regex into a shared SYSTEM_REMINDER_REGEX constant.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/services/context/ObservationCompiler.ts

@@ -8,6 +8,7 @@ import path from 'path';
 import { existsSync, readFileSync } from 'fs';
 import { SessionStore } from '../sqlite/SessionStore.js';
 import { logger } from '../../utils/logger.js';
+import { SYSTEM_REMINDER_REGEX } from '../../utils/tag-stripping.js';
 import { CLAUDE_CONFIG_DIR } from '../../shared/paths.js';
 import type {
   ContextConfig,
@@ -164,7 +165,7 @@ export function extractPriorMessages(transcriptPath: string): PriorMessages {
               text += block.text;
             }
           }
-          text = text.replace(/<system-reminder>[\s\S]*?<\/system-reminder>/g, '').trim();
+          text = text.replace(SYSTEM_REMINDER_REGEX, '').trim();
           if (text) {
             lastAssistantMessage = text;
             break;

src/shared/transcript-parser.ts

@@ -1,5 +1,6 @@
 import { readFileSync, existsSync } from 'fs';
 import { logger } from '../utils/logger.js';
+import { SYSTEM_REMINDER_REGEX } from '../utils/tag-stripping.js';
 
 /**
  * Extract last message of specified role from transcript JSONL file
@@ -48,7 +49,7 @@ export function extractLastMessage(
         }
 
         if (stripSystemReminders) {
-          text = text.replace(/<system-reminder>[\s\S]*?<\/system-reminder>/g, '');
+          text = text.replace(SYSTEM_REMINDER_REGEX, '');
           text = text.replace(/\n{3,}/g, '\n\n').trim();
         }
 

src/utils/tag-stripping.ts

@@ -8,6 +8,8 @@
  *    (allows users to mark content they don't want persisted)
  * 3. <system_instruction> / <system-instruction> - Conductor-injected system instructions
  *    (should not be persisted to memory)
+ * 4. <system-reminder> - Claude Code-injected system reminders
+ *    (CLAUDE.md contents, deferred tool lists, etc. — should not be persisted)
  *
  * EDGE PROCESSING PATTERN: Filter at hook layer before sending to worker/storage.
  * This keeps the worker service simple and follows one-way data stream.
@@ -15,6 +17,12 @@
 
 import { logger } from './logger.js';
 
+/**
+ * Regex to match <system-reminder> tags and their content.
+ * Exported for use by transcript parsers that strip system-reminder at read-time.
+ */
+export const SYSTEM_REMINDER_REGEX = /<system-reminder>[\s\S]*?<\/system-reminder>/g;
+
 /**
  * Maximum number of tags allowed in a single content block
  * This protects against ReDoS (Regular Expression Denial of Service) attacks
@@ -31,7 +39,8 @@ function countTags(content: string): number {
   const contextCount = (content.match(/<claude-mem-context>/g) || []).length;
   const systemInstructionCount = (content.match(/<system_instruction>/g) || []).length;
   const systemInstructionHyphenCount = (content.match(/<system-instruction>/g) || []).length;
-  return privateCount + contextCount + systemInstructionCount + systemInstructionHyphenCount;
+  const systemReminderCount = (content.match(/<system-reminder>/g) || []).length;
+  return privateCount + contextCount + systemInstructionCount + systemInstructionHyphenCount + systemReminderCount;
 }
 
 /**
@@ -55,6 +64,7 @@ function stripTagsInternal(content: string): string {
     .replace(/<private>[\s\S]*?<\/private>/g, '')
     .replace(/<system_instruction>[\s\S]*?<\/system_instruction>/g, '')
     .replace(/<system-instruction>[\s\S]*?<\/system-instruction>/g, '')
+    .replace(SYSTEM_REMINDER_REGEX, '')
     .trim();
 }
 

src/utils/transcript-parser.ts

@@ -5,6 +5,7 @@
 
 import { readFileSync } from 'fs';
 import { logger } from './logger.js';
+import { SYSTEM_REMINDER_REGEX } from './tag-stripping.js';
 import type {
   TranscriptEntry,
   UserTranscriptEntry,
@@ -163,7 +164,7 @@ export class TranscriptParser {
 
       if (filterSystemReminders) {
         // Filter out system-reminder tags and their content
-        text = text.replace(/<system-reminder>[\s\S]*?<\/system-reminder>/g, '');
+        text = text.replace(SYSTEM_REMINDER_REGEX, '');
         // Clean up excessive whitespace
         text = text.replace(/\n{3,}/g, '\n\n').trim();
       }