Add a mandatory community guidelines acceptance screen that users must
complete after accepting the EULA and before accessing the app. This
follows the same fail-closed pattern as the EULA gate.

Changes:
- Add community guidelines document (assets/legal/community-guidelines.md)
- Add CommunityGuidelinesProvider with versioned acceptance tracking
- Add CommunityGuidelinesScreen with scroll-to-bottom, checkbox, and
accept flow matching the EULA screen pattern
- Update router redirect chain: EULA → Community Guidelines → App
- Add "Community Guidelines" view-only link to profile settings menu
- Add Sentry error reporting to EULA provider
- Improve EULA screen: teal accent color, better link error handling,
empty content retry state
- Bump version to 1.0.5+6

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

Increment app version and build number for the next release.

Changes:
- Bump version from 1.0.4+4 to 1.0.5+5

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

Update EULA Section 5 to explicitly state zero-tolerance policy for
objectionable content and abusive users, including account termination
consequences. Add references to in-app blocking and reporting features
that empower users to manage their experience.

Changes:
- Add zero-tolerance policy statement for objectionable content
- Document account termination for abusive behavior
- Reference user blocking feature and its immediate effect
- Reference in-app content reporting to the Coves Team

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

Add a mandatory EULA acceptance flow that blocks app access until the
user scrolls through and agrees to the End User License Agreement.
The EULA is rendered from a bundled markdown file and supports
versioning so users can be re-prompted when terms change.

Changes:
- Add EulaProvider with versioned acceptance tracking via shared_preferences
- Add EulaScreen with scroll-to-bottom requirement, checkbox, and accept button
- Integrate EULA gate into GoRouter redirect logic in main.dart
- Add view-only EULA access from profile settings sheet
- Change project license from GPL v3 to AGPL v3
- Add flutter_markdown dependency for EULA rendering
- Fix getProfile XRPC method casing in API service and model comment

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

Add ability to block/unblock users and communities from post and comment
overflow menus with optimistic UI updates and rollback on failure.

Changes:
- Add BlockProvider with optimistic toggle, pending state, and auto-clear on sign-out
- Add blockUser/unblockUser/blockCommunity/unblockCommunity API methods
- Add shared block_action_helpers with auth check, confirmation dialog, and snackbar feedback
- Add block menu items to post card (user + community) and comment card (user)
- Add block error message to ErrorMessage
- Register BlockProvider in main.dart
- Add haptic feedback on comment card tap

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

Introduce tablet-optimized layouts using a NavigationRail on larger screens
and constrained content widths for improved readability.

Changes:
- Add ResponsiveUtils utility class with tablet detection (600dp breakpoint)
and maxContentWidth constant (640px for optimal line length)
- Replace bottom navigation with NavigationRail on tablets in MainShellScreen
- Constrain feed content to maxContentWidth on tablets across all screens:
- FeedPage, CommunityFeedScreen, ProfileScreen posts/comments
- PostDetailScreen post card and comment threads
- CommunitiesScreen placeholder content
- Use wrapForTablet helper for consistent responsive wrapping

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Replace string-based error pattern matching with type-based matching against
the ApiException hierarchy. This provides more reliable error handling and
cleaner call sites throughout the app.

Changes:
- Rewrite ErrorMessages to use ApiException types (Auth, Network, Server, etc.)
- Add ErrorMessage class with context-specific methods (vote, comment, subscription, etc.)
- Add isAuthError() helper for sign-in prompt flows
- Simplify exception handling in community_feed_screen, post_detail_screen
- Update comment_card and post_card_actions to use new error utilities
- Configure iOS release signing (bundle ID: social.coves)
- Add ExportOptions.plist for App Store Connect uploads

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>