Restrict local imports to registered uploads

[bcotrim]

Related issues

• Related to code scanning alert #221

How AI was used in this PR

Codex helped inspect the CodeQL taint flow, implement the upload registry, and run automated verification. I reviewed the diff and manually confirmed that fabricated upload paths are rejected.

Proposed Changes

• Restrict local-web imports and cleanup to backup files created by the current server, preventing request-supplied paths from reaching filesystem operations.
• Make uploaded backup paths single-use so fabricated or replayed paths are rejected without affecting the normal import flow.

Testing Instructions

1. Build the CLI and start the local API server from this branch:

   npm run cli:build
   npm run cli:build:ui
   node apps/cli/dist/cli/main.mjs ui --no-open

2. In another terminal, get the ID of an existing Studio site:

   SITE_ID=$(curl -sS http://127.0.0.1:8081/api/sites | jq -r '.[0].id')
   echo "$SITE_ID"

3. Submit an import request with a fabricated upload path:

   curl -i -X POST \
     -H 'Content-Type: application/json' \
     -d '{"path":"/tmp/studio-upload-fake/backup.sql"}' \
     "http://127.0.0.1:8081/api/sites/$SITE_ID/import"

4. Confirm the response is HTTP/1.1 400 Bad Request with:

   {"error":"Unknown backup path"}

5. Start the local web UI with npm run dev:local --workspace=apps/ui, open http://localhost:5400, import a backup through Add site → Import from a backup, and confirm the normal import flow still completes.

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[wpmobilebot]

📊 Performance Test Results

Comparing ce4a1c3 vs trunk

app-size

Metric	trunk	ce4a1c3	Diff	Change
App Size (Mac)	1362.04 MB	1362.04 MB	0.00 MB	⚪ 0.0%

site-editor

Metric	trunk	ce4a1c3	Diff	Change
load	1081 ms	1093 ms	+12 ms	⚪ 0.0%

site-startup

Metric	trunk	ce4a1c3	Diff	Change
siteCreation	7011 ms	7012 ms	+1 ms	⚪ 0.0%
siteStartup	2354 ms	2351 ms	3 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[nightnei]

Left 1 NIT comment

LGTM and works as expected:

1. 
2. And the import works well too