Audit string metadata and align Swahili translation parity

**Describe the tech debt**
User-facing strings (like tree_saved and sync_blocked) are incorrectly locked with translatable="false", and app_version uses hardcoded English. This prevents proper Swahili localization.

**Expected Outcome**
Ensure our base strings.xml correctly identifies translatable content and that the Swahili locale (values-sw) is up to date.

**Tasks**
- [x] Audit English strings.xml:** Locate visible strings marked with `translatable="false"` (e.g., `tree_saved`, `sync_blocked`) and remove the attribute.
- [x] Refactor app_version:** Change the base string to `%1$s (%2$d)` and set it to `translatable="false"` to remove hardcoded English words.
- [x] Update Swahili Parity:** Open the Translations Editor in Android Studio to find the newly unlocked keys (highlighted in red) and add the missing Swahili translations to `values-sw/strings.xml`.