feat(android): Add instrumentation logs for prefetch investigation

Add comprehensive instrumentation to diagnose why native fetcher
is not being called during prefetch operations.

Instrumentation Added:
- TimeSafariApplication: Log app initialization, fetcher registration,
  and verification with process ID and timestamps
- TimeSafariNativeFetcher: Log configuration, fetch start, source
  resolution (native vs fallback), and write completion
- Diagnostic script: Filter logcat for prefetch-related events
- Investigation summary: Document root cause hypotheses and
  diagnostic checklist

Log Tags:
- APP|ON_CREATE: App initialization timing and process info
- FETCHER|REGISTER_START/REGISTERED: Fetcher registration lifecycle
- FETCHER|CONFIGURE_START/CONFIGURE_COMPLETE: Configuration tracking
- PREFETCH|START/SOURCE/WRITE_OK: Prefetch operation tracking
- DISPLAY|START/LOOKUP: Display worker tracking (future)
- STORAGE|POST_PREFETCH/PRE_DISPLAY: Storage verification (future)

This instrumentation will help diagnose:
1. Registration timing issues (worker before onCreate)
2. Fetcher resolution failures (null fetcher)
3. Process mismatches (multi-process issues)
4. ID schema inconsistencies (prefetch vs display)
5. Storage persistence issues (content not saved)

Author: Matthew Raymer

android/app/src/main/java/app/timesafari/TimeSafariApplication.java

@@ -27,14 +27,44 @@ public class TimeSafariApplication extends Application {
     public void onCreate() {
         super.onCreate();
         
+        // Instrumentation: Log app initialization with process info
+        int pid = android.os.Process.myPid();
+        String processName = getApplicationInfo().processName;
+        Log.i(TAG, String.format(
+            "APP|ON_CREATE ts=%d pid=%d processName=%s",
+            System.currentTimeMillis(),
+            pid,
+            processName
+        ));
+        
         Log.i(TAG, "Initializing TimeSafari Application");
         
         // Register native fetcher with application context
         Context context = getApplicationContext();
         NativeNotificationContentFetcher nativeFetcher = 
             new TimeSafariNativeFetcher(context);
+        
+        // Instrumentation: Log before registration
+        Log.i(TAG, String.format(
+            "FETCHER|REGISTER_START instanceHash=%d ts=%d",
+            nativeFetcher.hashCode(),
+            System.currentTimeMillis()
+        ));
+        
         DailyNotificationPlugin.setNativeFetcher(nativeFetcher);
         
+        // Instrumentation: Verify registration succeeded
+        NativeNotificationContentFetcher verified = 
+            DailyNotificationPlugin.getNativeFetcherStatic();
+        boolean registered = (verified != null && verified == nativeFetcher);
+        
+        Log.i(TAG, String.format(
+            "FETCHER|REGISTERED providerKey=DailyNotificationPlugin instanceHash=%d registered=%s ts=%d",
+            nativeFetcher.hashCode(),
+            registered,
+            System.currentTimeMillis()
+        ));
+        
         Log.i(TAG, "Native fetcher registered: " + nativeFetcher.getClass().getName());
     }
 }

android/app/src/main/java/app/timesafari/TimeSafariNativeFetcher.java

@@ -92,10 +92,31 @@ public class TimeSafariNativeFetcher implements NativeNotificationContentFetcher
      */
     @Override
     public void configure(String apiBaseUrl, String activeDid, String jwtToken) {
+        // Instrumentation: Log configuration start
+        int pid = android.os.Process.myPid();
+        Log.i(TAG, String.format(
+            "FETCHER|CONFIGURE_START instanceHash=%d pid=%d ts=%d",
+            this.hashCode(),
+            pid,
+            System.currentTimeMillis()
+        ));
+        
         this.apiBaseUrl = apiBaseUrl;
         this.activeDid = activeDid;
         this.jwtToken = jwtToken;
         
+        // Instrumentation: Log configuration completion
+        boolean configured = (apiBaseUrl != null && activeDid != null && jwtToken != null);
+        Log.i(TAG, String.format(
+            "FETCHER|CONFIGURE_COMPLETE instanceHash=%d configured=%s apiBaseUrl=%s activeDid=%s jwtLength=%d ts=%d",
+            this.hashCode(),
+            configured,
+            apiBaseUrl != null ? apiBaseUrl : "null",
+            activeDid != null ? activeDid.substring(0, Math.min(30, activeDid.length())) + "..." : "null",
+            jwtToken != null ? jwtToken.length() : 0,
+            System.currentTimeMillis()
+        ));
+        
         // Enhanced logging for JWT diagnostic purposes
         Log.i(TAG, "TimeSafariNativeFetcher: Configured with API: " + apiBaseUrl);
         if (activeDid != null) {
@@ -122,6 +143,18 @@ public class TimeSafariNativeFetcher implements NativeNotificationContentFetcher
     public CompletableFuture<List<NotificationContent>> fetchContent(
             @NonNull FetchContext context) {
         
+        // Instrumentation: Log fetch start with context
+        int pid = android.os.Process.myPid();
+        Log.i(TAG, String.format(
+            "PREFETCH|START id=%s notifyAt=%d trigger=%s instanceHash=%d pid=%d ts=%d",
+            context.scheduledTime != null ? "daily_" + context.scheduledTime : "unknown",
+            context.scheduledTime != null ? context.scheduledTime : 0,
+            context.trigger,
+            this.hashCode(),
+            pid,
+            System.currentTimeMillis()
+        ));
+        
         Log.d(TAG, "TimeSafariNativeFetcher: Fetch triggered - trigger=" + context.trigger +
             ", scheduledTime=" + context.scheduledTime + ", fetchTime=" + context.fetchTime);
         
@@ -143,10 +176,25 @@ public class TimeSafariNativeFetcher implements NativeNotificationContentFetcher
             try {
                 // Check if configured
                 if (apiBaseUrl == null || activeDid == null || jwtToken == null) {
+                    Log.e(TAG, String.format(
+                        "PREFETCH|SOURCE from=fallback reason=not_configured apiBaseUrl=%s activeDid=%s jwtToken=%s ts=%d",
+                        apiBaseUrl != null ? "set" : "null",
+                        activeDid != null ? "set" : "null",
+                        jwtToken != null ? "set" : "null",
+                        System.currentTimeMillis()
+                    ));
                     Log.e(TAG, "TimeSafariNativeFetcher: Not configured. Call configureNativeFetcher() from TypeScript first.");
                     return Collections.emptyList();
                 }
                 
+                // Instrumentation: Log native fetcher usage
+                Log.i(TAG, String.format(
+                    "PREFETCH|SOURCE from=native instanceHash=%d apiBaseUrl=%s ts=%d",
+                    this.hashCode(),
+                    apiBaseUrl,
+                    System.currentTimeMillis()
+                ));
+                
                 Log.i(TAG, "TimeSafariNativeFetcher: Starting fetch from " + apiBaseUrl + ENDORSER_ENDPOINT);
                 
                 // Build request URL
@@ -226,6 +274,14 @@ public class TimeSafariNativeFetcher implements NativeNotificationContentFetcher
                     Log.i(TAG, "TimeSafariNativeFetcher: Successfully fetched " + contents.size() + 
                         " notification(s)");
                     
+                    // Instrumentation: Log successful fetch
+                    Log.i(TAG, String.format(
+                        "PREFETCH|WRITE_OK id=%s items=%d ts=%d",
+                        context.scheduledTime != null ? "daily_" + context.scheduledTime : "unknown",
+                        contents.size(),
+                        System.currentTimeMillis()
+                    ));
+                    
                     return contents;
                     
                 } else {

docs/prefetch-investigation-summary.md

@@ -0,0 +1,109 @@
+# Prefetch Investigation Summary
+
+## Problem Statement
+
+The daily notification prefetch job (T-5 min) is not calling the native fetcher, resulting in:
+- `from: null` in prefetch logs
+- Fallback/mock content being used
+- `DISPLAY_SKIP content_not_found` at notification time
+- Storage empty (`[]`) when display worker runs
+
+## Root Cause Hypothesis
+
+Based on the directive analysis, likely causes (ranked):
+
+1. **Registration Timing**: Prefetch worker runs before `Application.onCreate()` completes
+2. **Discovery Failure**: Worker resolves fetcher to `null` (wrong scope, process mismatch)
+3. **Persistence Bug**: Content written but wiped/deduped before display
+4. **ID Mismatch**: Prefetch writes `notify_...` but display looks for `daily_...`
+
+## Instrumentation Added
+
+### TimeSafariApplication.java
+- `APP|ON_CREATE ts=... pid=... processName=...` - App initialization timing
+- `FETCHER|REGISTER_START instanceHash=... ts=...` - Before registration
+- `FETCHER|REGISTERED providerKey=... instanceHash=... registered=... ts=...` - After registration with verification
+
+### TimeSafariNativeFetcher.java
+- `FETCHER|CONFIGURE_START instanceHash=... pid=... ts=...` - Configuration start
+- `FETCHER|CONFIGURE_COMPLETE instanceHash=... configured=... apiBaseUrl=... activeDid=... jwtLength=... ts=...` - Configuration completion
+- `PREFETCH|START id=... notifyAt=... trigger=... instanceHash=... pid=... ts=...` - Fetch start
+- `PREFETCH|SOURCE from=native/fallback reason=... ts=...` - Source resolution
+- `PREFETCH|WRITE_OK id=... items=... ts=...` - Successful fetch
+
+## Diagnostic Tools
+
+### Log Filtering Script
+```bash
+./scripts/diagnose-prefetch.sh app.timesafari.app
+```
+
+Filters logcat for:
+- `APP|ON_CREATE`
+- `FETCHER|*`
+- `PREFETCH|*`
+- `DISPLAY|*`
+- `STORAGE|*`
+
+### Manual Filtering
+```bash
+adb logcat | grep -E "APP\|ON_CREATE|FETCHER\||PREFETCH\||DISPLAY\||STORAGE\|"
+```
+
+## Investigation Checklist
+
+### A. App/Plugin Initialization Order
+- [ ] Confirm `APP|ON_CREATE` appears before `PREFETCH|START`
+- [ ] Verify `FETCHER|REGISTERED registered=true`
+- [ ] Check for multiple `onCreate` invocations (process restarts)
+- [ ] Confirm single process (no `android:process` on workers)
+
+### B. Prefetch Worker Resolution
+- [ ] Check `PREFETCH|SOURCE from=native` (not `from=fallback`)
+- [ ] Verify `instanceHash` matches between registration and fetch
+- [ ] Compare `pid` values (should be same process)
+- [ ] Check `FETCHER|CONFIGURE_COMPLETE configured=true` before prefetch
+
+### C. Storage & Persistence
+- [ ] Verify `PREFETCH|WRITE_OK items>=1`
+- [ ] Check storage logs for content persistence
+- [ ] Compare prefetch ID vs display lookup ID (must match)
+
+### D. ID Schema Consistency
+- [ ] Prefetch ID format: `daily_<epoch>` or `notify_<epoch>`
+- [ ] Display lookup ID format: must match prefetch ID
+- [ ] Verify ID derivation rules are consistent
+
+## Next Steps
+
+1. **Run diagnostic script** during a notification cycle
+2. **Analyze logs** for timing issues and process mismatches
+3. **If fetcher is null**: Implement Fix #2 (Pass Fetcher Context With Work) or Fix #3 (Process-Safe DI)
+4. **If ID mismatch**: Normalize ID schema across prefetch and display
+5. **If storage issue**: Add transactional writes and read-after-write verification
+
+## Expected Log Flow (Success Case)
+
+```
+APP|ON_CREATE ts=... pid=... processName=app.timesafari.app
+FETCHER|REGISTER_START instanceHash=... ts=...
+FETCHER|REGISTERED providerKey=DailyNotificationPlugin instanceHash=... registered=true ts=...
+FETCHER|CONFIGURE_START instanceHash=... pid=... ts=...
+FETCHER|CONFIGURE_COMPLETE instanceHash=... configured=true ... ts=...
+PREFETCH|START id=daily_... notifyAt=... trigger=prefetch instanceHash=... pid=... ts=...
+PREFETCH|SOURCE from=native instanceHash=... apiBaseUrl=... ts=...
+PREFETCH|WRITE_OK id=daily_... items=1 ts=...
+STORAGE|POST_PREFETCH total=1 ids=[daily_...]
+DISPLAY|START id=daily_...
+STORAGE|PRE_DISPLAY total=1 ids=[daily_...]
+DISPLAY|LOOKUP result=hit id=daily_...
+```
+
+## Failure Indicators
+
+- `PREFETCH|SOURCE from=fallback` - Native fetcher not resolved
+- `PREFETCH|SOURCE from=null` - Fetcher registration failed
+- `FETCHER|REGISTERED registered=false` - Registration verification failed
+- `STORAGE|PRE_DISPLAY total=0` - Content not persisted
+- `DISPLAY|LOOKUP result=miss` - ID mismatch or content cleared
+

scripts/diagnose-prefetch.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+#
+# Diagnostic script for daily notification prefetch issues
+# Filters logcat output for prefetch-related instrumentation logs
+#
+# Usage:
+#   ./scripts/diagnose-prefetch.sh [package_name]
+#
+# Example:
+#   ./scripts/diagnose-prefetch.sh app.timesafari.app
+#
+
+set -e
+
+PACKAGE_NAME="${1:-app.timesafari.app}"
+
+echo "🔍 Daily Notification Prefetch Diagnostic Tool"
+echo "=============================================="
+echo ""
+echo "Package: $PACKAGE_NAME"
+echo "Filtering for instrumentation tags:"
+echo "  - APP|ON_CREATE"
+echo "  - FETCHER|*"
+echo "  - PREFETCH|*"
+echo "  - DISPLAY|*"
+echo "  - STORAGE|*"
+echo ""
+echo "Press Ctrl+C to stop"
+echo ""
+
+# Filter logcat for instrumentation tags
+adb logcat -c  # Clear logcat buffer first
+
+adb logcat | grep -E "APP\|ON_CREATE|FETCHER\||PREFETCH\||DISPLAY\||STORAGE\||DailyNotification|TimeSafariApplication|TimeSafariNativeFetcher" | \
+  grep -i "$PACKAGE_NAME\|TimeSafari\|DailyNotification"
+