fix: Saved Connections Lost

[ohansyah]

Issue #913 All Saved Connections lost when opening a second window

Root cause
The connections store uses electron-store with encryption to protect passwords. The encryption key was managed through safeStorage (Electron's OS keychain API). On Flatpak/Linux where safeStorage is unavailable, the key couldn't be persisted:

• set-key handler silently dropped the key when safeStorage was unavailable
• get-key returned false when safeStorage was unavailable
• A second window or app restart would generate a different encryption key
• clearInvalidConfig: true on the store would then silently delete the encrypted file when decryption failed with the wrong key permanent data loss

Changes made
src/main/ipc-handlers/application.ts (main process key persistence):

• set-key: Always persists the key now. If safeStorage is available, encrypts it; otherwise stores the key as plain text in the session store (same directory, same file-system protection).
• get-key: Always reads from the store. Tries safeStorage decryption first, falls back to raw key read if unavailable or decryption fails.

src/renderer/stores/connections.ts (renderer key retrieval + data safety):

• Refactored key retrieval into getEncryptionKey() always uses the main process as the source of truth, with localStorage as a fast cache.
• Wrapped store creation in createPersistentStore() if the store file can't be decrypted (e.g., real corruption), it backs up the file with a .corrupt extension before resetting, rather than silently deleting it.

Result

• Second windows and app restarts now always get the same encryption key
• clearInvalidConfig: true can no longer trigger on key mismatch only on genuine file corruption
• In the worst case, a backup file is preserved for manual recovery