docs(roadmap): mark WebDAV ranged-PUT and trash-walk fixes done

ROADMAP.md

@@ -136,7 +136,7 @@ Order = user-visible value first; each ships with backend + UI + tests.
 ## 5. Phase C — security + quality
 
 - Own security review on top of upstream fixes: session/token entropy audit, SSRF guard re-test (NAT64 class), rate limiting on auth endpoints
-- Fix upstream bug backlog by impact: #3574 OOM (trash_bin_collect streaming), #3118/#3005 WebDAV large-file, ~~#3375 SMTP auth discovery~~ (done — `smtp_auth` setting)
+- Fix upstream bug backlog by impact: ~~#3574 OOM~~ (done — paged tree walk + batched delete), ~~#3118/#3005 WebDAV large-file~~ (done — Content-Range assembly into one session; non-local policies get honest 501; single-PUT giant-file 500s are proxy/client timeouts, not fixable server-side), ~~#3375 SMTP auth discovery~~ (done — `smtp_auth` setting)
 - #3454 (PG FK on upload) is **Pro-only** — `audit_logs` doesn't exist in this codebase. When B.5 adds our own audit log: insert the audit row in the same tx *after* the file row, never before.
 - `desloppify` + `security-reviewer` passes; scorecard appended to README