v1.5.5: terminal zoom, font fallback, copy feedback

- Ctrl+wheel/Ctrl±/Ctrl+0 font zoom (6-28), persisted in settings.json
- Font fallback: Cascadia Mono → Consolas → Courier New (per platform)
- Visual "Copied!" flash in status bar on copy
- Closes audit items #27 (copy feedback) and #29 (font fallback)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/server_store.py

@@ -49,6 +49,7 @@ class ServerStore:
         self._statuses_lock = threading.Lock()
         self._file_lock = threading.Lock()
         self._last_backup_time: float = 0
+        self._terminal_font_size: int = 11
         self._servers_file: str = DEFAULT_SERVERS_FILE
         self._load_settings()
         self._load()
@@ -68,6 +69,7 @@ class ServerStore:
                 lang = settings.get("language", "en")
                 i18n.set_language(lang)
                 self._check_interval = settings.get("check_interval", 60)
+                self._terminal_font_size = settings.get("terminal_font_size", 11)
             except json.JSONDecodeError:
                 log.warning("Corrupted settings.json, using defaults")
             except Exception as e:
@@ -80,6 +82,7 @@ class ServerStore:
             "servers_path": self._servers_file,
             "language": i18n.get_language(),
             "check_interval": self._check_interval,
+            "terminal_font_size": self._terminal_font_size,
         }
         try:
             tmp = SETTINGS_FILE + ".tmp"
@@ -301,3 +304,12 @@ class ServerStore:
     def get_status(self, alias: str) -> str:
         with self._statuses_lock:
             return self._statuses.get(alias, "unknown")
+
+    # ── Terminal font size ────────────────────────────────
+
+    def get_terminal_font_size(self) -> int:
+        return self._terminal_font_size
+
+    def set_terminal_font_size(self, size: int):
+        self._terminal_font_size = max(6, min(28, size))
+        self._save_settings()