Add Deck browsing feature with controller, UI, routing, and format helpers

[ercmine]

Motivation

• Introduce a swipable "Deck" experience to browse session suggestions and integrate it into existing sessions flows.
• Provide client-side telemetry and location-aware fetching for deck results and a small set of UI helper formatters.

Description

• Added a full Deck feature including state (deck_state.dart), controller (deck_controller.dart) with telemetry, location and repository integration, and a new route at /sessions/:id/deck wired into router.dart and session_page.dart.
• Implemented the Deck UI in deck_page.dart and a set of widgets for cards and details (deck_card.dart, deck_card_skeleton.dart, deck_actions_bar.dart, card_details_sheet.dart, and several small badges/pills), and hooked link launching into existing linkLauncherProvider usage.
• Registered a deckControllerProvider in providers/app_providers.dart, added format helpers in core/format/formatters.dart, and updated pubspec.yaml to include flutter_card_swiper, cached_network_image, and collection dependencies.
• Added UI behaviors such as loading/fallback states, undo stack, batching/merge logic for plans, and telemetry enqueue/flush calls to the existing telemetry repository API.

Testing

• Ran flutter analyze to ensure static analysis and imports are correct and it completed successfully.
• Ran flutter test and unit/widget tests completed successfully (no failing tests).

---

Codex Task

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: cf1bf2da4e

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Reset swipe history when refreshing deck

refresh() clears plans and cursor state but leaves undoStack (and shownPlanIds) intact, so after a retry/full refresh users can still undo into cards from the previous deck and telemetry position tracking continues from stale history. This leaks old session state into a fresh load and makes deck behavior inconsistent after refresh.

Useful? React with 👍 / 👎.