* security: fix five vulnerabilities (GHSA-779p-m5rp-r4h4)
- CVE-2026-56670: force download of SVG/XML responses on /view to prevent stored XSS
- CVE-2026-56671: contain /experiment/models/preview reads within the model folder
- CVE-2026-56672: stop inline rendering of uploaded /userdata/{file} content
- CVE-2026-56673: prevent path traversal in get_annotated_filepath (LoadImage /prompt input)
- CVE-2026-56674: reject opaque/null Origin to close the CSRF middleware bypass
Adds regression tests under tests-unit/security_test/ covering all five.
* security: address review feedback on GHSA-779p fixes
- Fix Windows CI failure in test_get_annotated_filepath: compare against
os.path.abspath(...) to match the intentional abspath normalization added
by the traversal hardening (abspath prepends the drive letter on Windows).
- origin_check: narrow the bare `except:` in is_loopback() to ValueError so
genuine interrupts aren't swallowed (review nit).
- origin_check: guard .port access in is_cross_origin_forbidden() so a
malformed/out-of-range port (e.g. Origin: http://127.0.0.1:99999) fails
closed with a 403 instead of surfacing an uncaught 500 in the middleware.
- server /view: escape backslash/quote in the Content-Disposition filename
(RFC 6266 quoted-string) so a filename containing a double quote can't
malform the response header.
* security: address CodeRabbit review feedback on GHSA-779p tests
- test #3: guard the symlink-escape test with a try/except skip so it no
longer errors on Windows CI where os.symlink needs elevated privileges /
Developer Mode (mirrors the guard in the sibling test #2).
- test #5: refresh the stale module docstring to describe the actual /view
gating (view_image closure calling folder_paths.is_dangerous_content_type,
the normalising check) instead of the bypassable raw set-membership test.
* revert(security): drop CVE-2026-56674 Origin: null CSRF change
Per maintainer review, the reported CSRF is already mitigated by the pre-existing
Sec-Fetch-Site: cross-site check for current browsers, and the null-origin
rejection risked breaking legitimate sandboxed-iframe embeds. Restores
origin_only_middleware and is_loopback in server.py to their prior state
(the Sec-Fetch-Site check is retained) and removes utils/origin_check.py and its
regression test. The other four GHSA-779p fixes are unaffected.
