polish: Digest Preferences UI — connection names, one gear, first-run (#108)

## Summary
- Pref cards show **human connection display names** instead of UUIDs
(`connectionName` on the preferences list DTO; client falls back to the
connections list, then UUID only if missing).
- Consolidate digest prefs entry to **one gear** in the Digest section
(removed competing bell; legacy global Schedule panel removed from the
top bar — schedule is per-preference in the prefs panel).
- Simplify persona / on-off / schedule UX in `DigestPreferencesPanel`
(compact labeled controls, no duplicate meta row).
- **First-run**: opening Digests with zero prefs (or none enabled)
auto-opens Digest Preferences once (`localStorage` key
`deepsql.digestPrefs.autoOpened.v1`).

Keeps seed/me, persona, and enable/disable APIs.

## Acceptance
- [x] Cards show names (e.g. `ec2-replica`), not UUIDs, when the name is
known
- [x] Single gear entry for Digest Preferences
- [x] Simplified persona / schedule / On-Off controls
- [x] First-run auto-open once when no/zero enabled prefs
- [x] Branch off latest `origin/main`; no force-push to main

## Test plan
- [ ] Open Digests → only one gear in the top bar; gear opens Digest
Preferences
- [ ] Pref cards show connection names for all known connections (not
only CURRENT)
- [ ] Toggle On/Off, change persona, change schedule presets; seed/me
still works
- [ ] Clear `localStorage['deepsql.digestPrefs.autoOpened.v1']`, ensure
zero enabled prefs → panel auto-opens once; reload does not reopen
- [ ] Backend: `GET /api/digest/preferences` includes `connectionName`

Author: venkateshsakamuri-lab

backend/src/main/java/com/dbaagent/controller/DigestPreferenceController.java

@@ -1,8 +1,11 @@
 package com.dbaagent.controller;
 
+import com.dbaagent.dto.DigestPreferenceResponse;
+import com.dbaagent.model.DatabaseConnection;
 import com.dbaagent.model.DigestDeliveryMethod;
 import com.dbaagent.model.PersonaTag;
 import com.dbaagent.model.UserDigestPreference;
+import com.dbaagent.repository.CredentialRepository;
 import com.dbaagent.service.DigestPreferenceSeedService;
 import com.dbaagent.service.security.AccessControlService;
 import com.dbaagent.service.UserDigestPreferenceService;
@@ -13,8 +16,12 @@
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.*;
 
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 /**
  * REST controller for managing per-user digest preferences.
@@ -32,21 +39,23 @@ public class DigestPreferenceController {
     private final AccessControlService accessControlService;
     private final DigestPreferenceSeedService seedService;
     private final SlackDailyDigestService digestService;
+    private final CredentialRepository credentialRepository;
 
     /**
-     * Get the current user's digest preferences.
+     * Get the current user's digest preferences (includes connection display names).
      */
     @GetMapping
-    public ResponseEntity<List<UserDigestPreference>> getMyPreferences() {
+    public ResponseEntity<List<DigestPreferenceResponse>> getMyPreferences() {
         String username = accessControlService.requireCurrentUsername();
-        return ResponseEntity.ok(preferenceService.getPreferencesForUser(username));
+        List<UserDigestPreference> prefs = preferenceService.getPreferencesForUser(username);
+        return ResponseEntity.ok(toResponses(prefs));
     }
 
     /**
      * Create a new digest preference for the current user.
      */
     @PostMapping
-    public ResponseEntity<UserDigestPreference> createPreference(@RequestBody CreatePreferenceRequest request) {
+    public ResponseEntity<DigestPreferenceResponse> createPreference(@RequestBody CreatePreferenceRequest request) {
         String username = accessControlService.requireCurrentUsername();
 
         DigestDeliveryMethod method;
@@ -80,14 +89,14 @@ public ResponseEntity<UserDigestPreference> createPreference(@RequestBody Create
             request.timezone
         );
 
-        return ResponseEntity.ok(preference);
+        return ResponseEntity.ok(toResponse(preference));
     }
 
     /**
      * Update an existing preference.
      */
     @PutMapping("/{id}")
-    public ResponseEntity<UserDigestPreference> updatePreference(
+    public ResponseEntity<DigestPreferenceResponse> updatePreference(
             @PathVariable Long id,
             @RequestBody UpdatePreferenceRequest request) {
 
@@ -112,14 +121,14 @@ public ResponseEntity<UserDigestPreference> updatePreference(
             request.timezone
         );
 
-        return ResponseEntity.ok(updated);
+        return ResponseEntity.ok(toResponse(updated));
     }
 
     /**
      * Enable or disable a preference.
      */
     @PatchMapping("/{id}/enabled")
-    public ResponseEntity<UserDigestPreference> setEnabled(
+    public ResponseEntity<DigestPreferenceResponse> setEnabled(
             @PathVariable Long id,
             @RequestBody Map<String, Boolean> body) {
 
@@ -138,7 +147,7 @@ public ResponseEntity<UserDigestPreference> setEnabled(
         }
 
         UserDigestPreference updated = preferenceService.setEnabled(id, enabled);
-        return ResponseEntity.ok(updated);
+        return ResponseEntity.ok(toResponse(updated));
     }
 
     /**
@@ -286,4 +295,58 @@ public record DigestStatusResponse(boolean perUserMode, long enabledPreferences,
     public ResponseEntity<Map<String, String>> handleBadRequest(IllegalArgumentException e) {
         return ResponseEntity.badRequest().body(Map.of("message", e.getMessage() != null ? e.getMessage() : "Bad request"));
     }
+
+    // ─────────────────────────────────────────────────────────────────────────
+    // Response mapping (connection display names)
+    // ─────────────────────────────────────────────────────────────────────────
+
+    private List<DigestPreferenceResponse> toResponses(List<UserDigestPreference> prefs) {
+        Map<String, String> namesById = resolveConnectionNames(prefs);
+        return prefs.stream()
+            .map(pref -> toResponse(pref, namesById))
+            .toList();
+    }
+
+    private DigestPreferenceResponse toResponse(UserDigestPreference pref) {
+        Map<String, String> namesById = resolveConnectionNames(List.of(pref));
+        return toResponse(pref, namesById);
+    }
+
+    private DigestPreferenceResponse toResponse(UserDigestPreference pref, Map<String, String> namesById) {
+        String connectionName = null;
+        if (pref.getConnectionId() != null) {
+            connectionName = namesById.get(pref.getConnectionId());
+        }
+        return DigestPreferenceResponse.builder()
+            .id(pref.getId())
+            .username(pref.getUsername())
+            .connectionId(pref.getConnectionId())
+            .connectionName(connectionName)
+            .enabled(pref.isEnabled())
+            .personaTag(pref.getPersonaTag() != null ? pref.getPersonaTag().name() : null)
+            .cronExpression(pref.getCronExpression())
+            .deliveryMethod(pref.getDeliveryMethod() != null ? pref.getDeliveryMethod().name() : null)
+            .timezone(pref.getTimezone())
+            .createdAt(pref.getCreatedAt())
+            .updatedAt(pref.getUpdatedAt())
+            .build();
+    }
+
+    private Map<String, String> resolveConnectionNames(List<UserDigestPreference> prefs) {
+        Set<String> ids = prefs.stream()
+            .map(UserDigestPreference::getConnectionId)
+            .filter(Objects::nonNull)
+            .filter(id -> !id.isBlank())
+            .collect(Collectors.toSet());
+        if (ids.isEmpty()) {
+            return Map.of();
+        }
+        Map<String, String> names = new HashMap<>();
+        for (DatabaseConnection conn : credentialRepository.findAllById(ids)) {
+            if (conn.getId() != null && conn.getConnectionName() != null) {
+                names.put(conn.getId(), conn.getConnectionName());
+            }
+        }
+        return names;
+    }
 }

backend/src/main/java/com/dbaagent/dto/DigestPreferenceResponse.java

@@ -0,0 +1,26 @@
+package com.dbaagent.dto;
+
+import lombok.Builder;
+import lombok.Value;
+
+import java.time.LocalDateTime;
+
+/**
+ * API view of a {@code UserDigestPreference} with a human-readable connection name.
+ */
+@Value
+@Builder
+public class DigestPreferenceResponse {
+    Long id;
+    String username;
+    String connectionId;
+    /** Display name for {@link #connectionId}; null when unknown or preference is connection-wide. */
+    String connectionName;
+    boolean enabled;
+    String personaTag;
+    String cronExpression;
+    String deliveryMethod;
+    String timezone;
+    LocalDateTime createdAt;
+    LocalDateTime updatedAt;
+}

docs/DIGEST_PREFERENCES.md

@@ -86,7 +86,7 @@ Note: Do not claim EMAIL or WhatsApp delivery is available. These are planned fo
 
 | Endpoint | Method | Description |
 |----------|--------|-------------|
-| `/api/digest/preferences` | GET | Get current user's preferences |
+| `/api/digest/preferences` | GET | Get current user's preferences (includes `connectionName`) |
 | `/api/digest/preferences` | POST | Create a new preference |
 | `/api/digest/preferences/{id}` | PUT | Update a preference |
 | `/api/digest/preferences/{id}/enabled` | PATCH | Enable/disable |
@@ -134,16 +134,17 @@ To migrate from legacy singleton mode to per-user mode:
 
 The digest preferences are accessible from:
 
-1. **Digest Section** (sidebar): Click the bell icon (🔔) to open preferences panel
-2. **Preferences Panel**: Create, edit, enable/disable, delete preferences
+1. **Digest Section** (sidebar): Click the **gear** (⚙) to open the preferences panel — single entry point (no competing bell)
+2. **First-run**: Opening Digests with zero preferences (or none enabled) auto-opens the panel once (`localStorage` flag)
+3. **Preferences Panel**: Create, edit, enable/disable, delete preferences
 
 ### Preferences Panel Features
 
-- View all your digest subscriptions
+- Pref cards show **connection display names** (API `connectionName`, with client-side fallback from the connections list; UUID only if name is missing)
 - Toggle digests on/off per connection
-- Change persona without recreating
+- Change persona and schedule inline (compact controls — no duplicate meta labels)
 - Quick schedule presets (8 AM, 9 AM, Noon, etc.) — stored on the preference and honored by the minute-tick scheduler
-- Seed for all your connections at once
+- Seed for all your connections at once (`POST /api/digest/preferences/seed/me`)
 
 ## Database Schema