chore(refactor): consolidate open refactoring PRs and apply code review fixes

[Himanth-reddy]

Summary of Changes

• Exception Safety & Cancellation Propagation:

  • WatchHistoryRepository: Rethrows CancellationException in primary save catch block.
  • DetailsViewModel: Preserves CancellationException propagation in episode save/watch progress handlers.
  • IptvRepository: Explicitly rethrows CancellationException in date formatting fallback logic.
  • AuthRepository: Narrows broad Instant.parse catch block to IllegalArgumentException and DateTimeParseException.

• TvDeviceAuth & Response Polling:

  • TvDeviceAuthRepository: Uses an explicit outer label (outerUse@) on status polling response use block so legacy 404 fallback exits the outer lambda directly without processing the 404 response.

• Data Models & Parsing:

  • IptvChannelStore: Safely parses requestHeaders_json as a JsonObject retaining non-null string entries.
  • IptvModels: Ensures safe collection immutability for channel request headers and snapshot models.
  • AuthRepository: Validates Netlify account sync responses, treating malformed/missing responses as failed uploads.

• UI & Settings Validation:

  • SettingsViewModel: Narrows regex validation try-catch blocks to PatternSyntaxException and IllegalArgumentException, returning boolean success status.
  • SettingsScreen: Closes quality filter editor modal only when validation succeeds.

Verification

• Built & compiled with ./gradlew :app:compileSideloadDebugKotlin (BUILD SUCCESSFUL).