Calls v1: Fix silent handleReconnect failures [MM-70184]

[bgardner8008]

Summary

• Publishes wsEventError back to the client when handleReconnect fails, so the client can fall back to a clean rejoin instead of silently retrying until its 30s reconnect budget expires and the session is orphaned.
• Switches getCallState in handleReconnect to read from the writer DB (fromWriter=true), fixing the replica-lag variant of the failure ("no call ongoing" / "session not found") that was the most common cause observed on the community hub during rolling deploys.

See MM-70184 for the full analysis, hub log evidence, and companion ticket MM-70185.

Test plan

• New TestHandleReconnect (5 subtests) covers the handleReconnect error paths directly: forbidden, no call ongoing, session not found, session belonging to a different user, and already-reconnected.
• New TestWebSocketMessageHasBeenPostedReconnectError verifies that wsEventError is published to the client's connection ID when the reconnect goroutine fails.
• make golangci-lint clean; full go test ./server/... passes.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 7978eaa9-9b32-4ec8-adbb-5f867647ed79

📥 Commits

Reviewing files that changed from the base of the PR and between c39546a and cddd0ac.

📒 Files selected for processing (2)

• server/websocket.go
• server/websocket_test.go

Included review availability: 2 reviews are currently available. Your included PR review attempts over the past 7 days set your current allowance at 5 reviews per hour.

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📝 Walkthrough

Walkthrough

Reconnect handling now loads enabled call state. Invalid reconnect requests are tested. Reconnect failures now send reliable wsEventError events to the affected connection.

Changes

Reconnect handling

Layer / File(s)	Summary
Reconnect state validation server/websocket.go, server/websocket_test.go	handleReconnect loads enabled call state. Tests cover denied access, missing calls or sessions, ownership mismatches, and duplicate reconnections.
Reconnect error reporting server/websocket.go, server/websocket_test.go	Reconnect failures publish reliable wsEventError events with the error text and connection ID. An integration test verifies the event.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to cddd0

The change reports reconnect failures to clients and reads reconnect state from the writer database, improving recovery behavior without any supplied current-head merge-blocking risk; no actionable merge-blocking risk remains.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the API area and the main fix for silent handleReconnect failures.
Description check	✅ Passed	The description directly explains the reconnect error notification, writer database change, and related tests.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch MM-70184-handle-reconnect

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 25.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 35.50%. Comparing base (eb708b4) to head (cddd0ac).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
server/websocket.go	25.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1283      +/-   ##
==========================================
+ Coverage   28.26%   35.50%   +7.24%     
==========================================
  Files         240      250      +10     
  Lines       13862    14294     +432     
  Branches     1643     1730      +87     
==========================================
+ Hits         3918     5075    +1157     
+ Misses       9501     8598     -903     
- Partials      443      621     +178     

Files with missing lines	Coverage Δ
server/websocket.go	33.40% <25.00%> (+5.73%)	⬆️

... and 78 files with indirect coverage changes

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