build(apple): enforce typed resources with SwiftLint

Add a focused .swiftlint.yml (custom rules only, no default style noise) flagging
raw String(localized:) / LocalizedStringKey / systemName|systemImage literals, and
wire it as a required pre-build phase that fails the build if SwiftLint is missing
(brew install swiftlint). The phase prepends the Homebrew bin dirs since Xcode runs
scripts with a minimal PATH. Runs clean on the current tree (0 violations).

apple/.swiftlint.yml

@@ -0,0 +1,27 @@
+# Focused lint for the native app: enforce the typed-resources convention only
+# (no default style rules, so this stays signal, not noise).
+only_rules:
+  - custom_rules
+
+included:
+  - VniDrop
+
+excluded:
+  - VniDrop/Generated
+
+custom_rules:
+  raw_localized_string:
+    name: "Raw localized key"
+    regex: 'String\(localized:\s*"'
+    message: "Use a typed L10n.* accessor, not a raw key string."
+    severity: warning
+  raw_localized_string_key:
+    name: "Raw LocalizedStringKey"
+    regex: 'LocalizedStringKey\("'
+    message: "Use a typed L10n.* accessor instead of a raw key."
+    severity: warning
+  raw_sf_symbol:
+    name: "Raw SF Symbol"
+    regex: 'system(Name|Image):\s*"'
+    message: "Use SFSafeSymbols: Image(systemSymbol:) or systemSymbol:."
+    severity: warning