feat: add SVG assets for toast notifications and update toast configu…

[HoshinoIzumi]

…ration

Summary

• Added icon + message styling to the shared toast component (toast-config.tsx), using the newly exported mascot icons (toast1/toast2/toast3.svg) for the error, success, and warning toast types.
• Registered the three SVGs in assets.ts as SVGIMAGES.toastFail / toastSuccess / toastWarning, following the existing asset-import convention.
• Kept the existing Toast.show({ type, text1 }) call sites unchanged — this only updates how the toast renders, not how it's triggered.
• Tweaked the success toast background/text color (#ECF6E3 / #9CD710) to match the new success icon's palette.

Release note

Toast notifications (task created, errors, warnings, etc.) now show a small icon alongside the message.

Status:

• User-facing — announce it
• Beta / partial — announce, but tagged as beta
• Hidden in production (feature-flagged / not enabled for users) — don't announce
• Internal only (refactor / infra / tests / CI / deps) — don't announce

[github-actions]

Test Results

98 tests   98 ✅  9s ⏱️
 1 suites   0 💤
 1 files     0 ❌

Results for commit 5e0d697.

♻️ This comment has been updated with latest results.

[github-actions]

Package	Line Rate	Branch Rate	Complexity	Health
BlotzTask	4%	34%	2443	❌
BlotzTask	4%	34%	2443	❌
Summary	4% (4132 / 101466)	34% (842 / 2488)	4886	❌