fix(app): session listing sorted by update time rather than id

[neriousy]

Issue for this PR

Closes #17474

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Makes the session list sorted by updated_at rather than id

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How did you verify your code works?

Load sessions -> load more

Screenshots / recordings

If this is a UI change, please include a screenshot or recording.

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

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[Copilot]

Pull request overview

This PR fixes session list ordering by removing client-side sorting by id and instead preserving/maintaining “most recently updated” ordering (as provided by the server and reinforced by client upsert logic).

Changes:

• Stop re-sorting fetched session lists by id, preserving server-provided order.
• Update session upsert/update paths to maintain recency ordering (updated time, then id as tiebreak).
• Adjust and add tests to reflect the new ordering behavior.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
packages/app/src/pages/layout/helpers.ts	Removes time-window/id-based sorting for root session lists; latest-session selection now sorts by updated time.
packages/app/src/pages/layout/helpers.test.ts	Updates tests for latest session selection; adds coverage for preserving store ordering of visible roots.
packages/app/src/pages/layout.tsx	Replaces binary-search deletion with linear lookup; updates latestRootSession call signature.
packages/app/src/context/sync.tsx	Removes id-sorting on fetch and replaces binary search usage on sessions with linear lookups + recency-aware insertion for roots.
packages/app/src/context/notification.tsx	Replaces binary-search session lookup with .find().
packages/app/src/context/global-sync/session-trim.ts	Stops reshaping lists by id; trims/dedupes while preserving fetched order and uses recency comparator utilities.
packages/app/src/context/global-sync/session-trim.test.ts	Updates expectations to match preserved fetched order and new root/child ordering.
packages/app/src/context/global-sync/event-reducer.ts	Adds recency-aware upsert logic for sessions and removes Binary.search dependency for session arrays.
packages/app/src/context/global-sync.tsx	Stops sorting fetched sessions by id before trimming/reconciling.

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