fix: canceling account edits still saves updated profile picture

[jenniyan]

Description

Profile picture is only officially updated after pressing save. Previously, it would be saved even if the user pressed Cancel on the account form.

Issues

Closes #185

---

Summary by cubic

Fixes the bug where canceling account or profile edits still saved a new profile picture. Previously, uploads committed immediately; now picture changes commit only on Save, and Cancel/exit keeps the original. Closes #185.

• Stage uploads for preview only; delete replaced or unsaved uploads on cancel/replace/exit, and never delete a committed picture.
• Prevent races by tagging requests with a session/request id; ignore and delete uploads that resolve after cancel/save (including uploads started during save).
• Make save atomic: commit the new picture on Save and then update the user; if the picture update fails, keep the prior picture and audit state unchanged.
• Treat the picture as dirty only if the key changes; show “Profile Picture → Updated” in Changed fields and include picture in audit snapshots when changed.
• While saving, disable Cancel (and Edit) and show Save loading in both the account drawer and profile view; add i18n for “Profile Picture” and “Updated” in en, es, fr, and zh.

^{Written for commit c174614. Summary will update on new commits.}

[cubic-dev-ai]

All reported issues were addressed across 7 files

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

All reported issues were addressed across 1 file (changes from recent commits).

<sub>Tip: Review your code locally with the cubic CLI to iterate faster.

Re-trigger cubic</sub>

[cubic-dev-ai]

All reported issues were addressed across 1 file (changes from recent commits).

<sub>Tip: Review your code locally with the cubic CLI to iterate faster.

Re-trigger cubic</sub>

[xgraceyan]

Did you get a chance to test it locally, now that the S3 bucket is working? I just tested it and it works for the "Accounts" page but not when I edit my own profile in /profile. Can we implement this fix in the Profile page as well?

[cubic-dev-ai]

All reported issues were addressed across 3 files (changes from recent commits).

<sub>Tip: Review your code locally with the cubic CLI to iterate faster.

Re-trigger cubic</sub>

[cubic-dev-ai]

All reported issues were addressed across 1 file (changes from recent commits).

<sub>Tip: Review your code locally with the cubic CLI to iterate faster.

Re-trigger cubic</sub>

[xgraceyan]

Is this ready for re-review? Lmk, just re-request a review from me whenever it's ready