fix(#252): gate outgoing DM to a blocked contact

Replace the DM composer with an "Unblock to message" notice bar when
the contact is blocked, so a block also stops outgoing DMs (previously
only incoming DMs/adverts were suppressed). Inline unblock restores the
composer. Adds block_composerNotice l10n string and documents the
outgoing-DM rule in block-contract-as-built.md §4.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/architecture/block-contract-as-built.md

@@ -66,6 +66,7 @@ API: `isBlocked(keyHex)`, `isNameBlocked(name)`, `block(keyHex)`, `unblock(keyHe
 | Surface | Rule |
 |---|---|
 | Incoming DM | drop + suppress notification when `senderKey ∈ blockedKeys` (on Offband, firmware already dropped it at receive — §7) |
+| Outgoing DM | **prevent sending** to a blocked contact — the DM composer is replaced by a notice bar with an inline **Unblock** action (you cannot message someone you've blocked without first unblocking). Chat history stays visible. |
 | Advert | suppress the new-advert notification for `blockedKeys`. **Do NOT discard the advert** — the contact-name update must keep flowing (self-heal, §5) |
 | Contacts / Discovery lists | **keep blocked entries VISIBLE** with a clear blocked indicator — a red block icon (`Icons.block`, circle-with-slash) + muted/greyed styling. **Do NOT hide them.** Inline unblock available. *(A "hide blocked entirely" toggle is a deliberate post-implementation follow-on, not v1.)* |
 | Channel message | hide per the resolution rule in §5 |

lib/l10n/app_en.arb

@@ -2602,5 +2602,6 @@
   "block_namesSection": "Blocked names",
   "block_namesHint": "Name-only blocks (channel senders) — each upgrades to a full block once we learn their key.",
   "block_offloadActive": "Firmware offload active — blocks sync to this radio",
-  "block_offloadStoreFull": "Radio block list full (32) — extra blocks stay app-only"
+  "block_offloadStoreFull": "Radio block list full (32) — extra blocks stay app-only",
+  "block_composerNotice": "You've blocked this contact"
 }

lib/l10n/app_localizations.dart

@@ -7887,6 +7887,12 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'Radio block list full (32) — extra blocks stay app-only'**
   String get block_offloadStoreFull;
+
+  /// No description provided for @block_composerNotice.
+  ///
+  /// In en, this message translates to:
+  /// **'You\'ve blocked this contact'**
+  String get block_composerNotice;
 }
 
 class _AppLocalizationsDelegate

lib/l10n/app_localizations_bg.dart

@@ -4618,4 +4618,7 @@ class AppLocalizationsBg extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_de.dart

@@ -4636,4 +4636,7 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_en.dart

@@ -4540,4 +4540,7 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_es.dart

@@ -4623,4 +4623,7 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_fr.dart

@@ -4652,4 +4652,7 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_hu.dart

@@ -4639,4 +4639,7 @@ class AppLocalizationsHu extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_it.dart

@@ -4628,4 +4628,7 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_ja.dart

@@ -4393,4 +4393,7 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_ko.dart

@@ -4394,4 +4394,7 @@ class AppLocalizationsKo extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_nl.dart

@@ -4603,4 +4603,7 @@ class AppLocalizationsNl extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_pl.dart

@@ -4640,4 +4640,7 @@ class AppLocalizationsPl extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_pt.dart

@@ -4616,4 +4616,7 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_ru.dart

@@ -4634,4 +4634,7 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_sk.dart

@@ -4599,4 +4599,7 @@ class AppLocalizationsSk extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_sl.dart

@@ -4597,4 +4597,7 @@ class AppLocalizationsSl extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_sv.dart

@@ -4572,4 +4572,7 @@ class AppLocalizationsSv extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_uk.dart

@@ -4635,4 +4635,7 @@ class AppLocalizationsUk extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/l10n/app_localizations_zh.dart

@@ -4267,4 +4267,7 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get block_offloadStoreFull =>
       'Radio block list full (32) — extra blocks stay app-only';
+
+  @override
+  String get block_composerNotice => 'You\'ve blocked this contact';
 }

lib/screens/chat_screen.dart

@@ -591,6 +591,9 @@ class _ChatScreenState extends State<ChatScreen> {
   }
 
   Widget _buildInputBar(MeshCoreConnector connector) {
+    if (context.watch<BlockService>().isBlocked(widget.contact.publicKeyHex)) {
+      return _buildBlockedBar();
+    }
     final maxBytes = maxContactMessageBytes();
     final colorScheme = Theme.of(context).colorScheme;
     final settings = context.watch<AppSettingsService>().settings;
@@ -736,6 +739,38 @@ class _ChatScreenState extends State<ChatScreen> {
     );
   }
 
+  Widget _buildBlockedBar() {
+    final colorScheme = Theme.of(context).colorScheme;
+    return Container(
+      padding: const EdgeInsets.all(8),
+      decoration: BoxDecoration(
+        color: colorScheme.surface,
+        border: Border(top: BorderSide(color: Theme.of(context).dividerColor)),
+      ),
+      child: SafeArea(
+        child: Row(
+          children: [
+            const SizedBox(width: 4),
+            Icon(Icons.block, color: colorScheme.error),
+            const SizedBox(width: 12),
+            Expanded(
+              child: Text(
+                context.l10n.block_composerNotice,
+                style: TextStyle(color: colorScheme.onSurfaceVariant),
+              ),
+            ),
+            TextButton(
+              onPressed: () => context.read<BlockService>().unblock(
+                widget.contact.publicKeyHex,
+              ),
+              child: Text(context.l10n.block_unblock),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
   Future<void> _sendMessage(MeshCoreConnector connector) async {
     final text = _textController.text.trim();
     if (text.isEmpty) return;

linux/flutter/generated_plugins.cmake

@@ -8,6 +8,7 @@ list(APPEND FLUTTER_PLUGIN_LIST
 
 list(APPEND FLUTTER_FFI_PLUGIN_LIST
   flserial
+  jni
 )
 
 set(PLUGIN_BUNDLED_LIBRARIES)

untranslated.json

@@ -49,7 +49,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "de": [
@@ -102,7 +103,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "es": [
@@ -155,7 +157,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "fr": [
@@ -208,7 +211,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "hu": [
@@ -261,7 +265,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "it": [
@@ -314,7 +319,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "ja": [
@@ -367,7 +373,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "ko": [
@@ -420,7 +427,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "nl": [
@@ -473,7 +481,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "pl": [
@@ -526,7 +535,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "pt": [
@@ -579,7 +589,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "ru": [
@@ -632,7 +643,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "sk": [
@@ -685,7 +697,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "sl": [
@@ -738,7 +751,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "sv": [
@@ -791,7 +805,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "uk": [
@@ -844,7 +859,8 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ],
 
   "zh": [
@@ -897,6 +913,7 @@
     "block_namesSection",
     "block_namesHint",
     "block_offloadActive",
-    "block_offloadStoreFull"
+    "block_offloadStoreFull",
+    "block_composerNotice"
   ]
 }

windows/flutter/generated_plugins.cmake

@@ -11,6 +11,7 @@ list(APPEND FLUTTER_PLUGIN_LIST
 list(APPEND FLUTTER_FFI_PLUGIN_LIST
   flserial
   flutter_local_notifications_windows
+  jni
 )
 
 set(PLUGIN_BUNDLED_LIBRARIES)