Summary

When a task's context is edited in an external editor and the saved content
exceeds pers.ContextMaxBytes (1 MiB), the textEditorClosed handler in
internal/ui/update.go removed the temporary file before the size check, so
the over-limit branch discarded the user's edits with no way to recover them.

This moves the size check ahead of the file removal. On the over-limit path the
temp file is now kept on disk, and the error message names its location so the
user can recover their text, shorten it, and re-open the editor. The success
path still removes the temp file exactly as before.

Why this matters

Issue #65 reports that editing a large context silently throws the work away.
As the issue puts it, "the main thing I would like is for work to not be lost."
The existing // TODO: allow reopening the text editor with the same content again at the over-limit branch confirmed this was the intended direction. The
1 MiB cap is unchanged; this is purely about not losing work.

Testing

• go build ./..., go vet ./..., gofmt -l . / gofumpt -l .: clean
• go test ./...: all packages pass
• Behavior:
  • Content under 1 MiB: saved normally, temp file removed (unchanged)
  • Content over 1 MiB: error names the preserved temp-file path, file remains on disk
  • Editor error / read error: existing paths preserved (temp file still removed on editor error)
  • Empty content with no prior context: still a no-op

Fixes #65

AI was used for assistance.