Add Phase 9C security hardening

Generate exact-hash SDK source overrides without modifying dependencies.
Harden
SSH allocation and algorithm policy, tighten web authentication cleanup,
and add
focused host contract tests and documentation.

docs/agent/code-map.md

@@ -17,6 +17,12 @@ This is a semantic map, not a complete file inventory. Start here, then read the
 - Files: `src/security_build_policy.c`, registration in `src/CMakeLists.txt`, diagnostic flags in `sdkconfig.defaults`; tests: `tests/security_build_policy/run.py` (optional `--sdkconfig-header` checks the generated configuration).
 - Compile-only guard: require no core dumps and silent panic reboot; reject panic/register output, panic/runtime GDB stubs and OCD-aware panic handling. No runtime allocation/task or physical JTAG restriction. Policy, operational profiles and target gates: [Phase 9 hardening](../security_hardening.md).
 
+## Source-pinned dependency corrections (Phase 9C)
+
+- Files: root `CMakeLists.txt` (after `project()`), `cmake/security_overrides.cmake`, `tools/security_overrides.py`; tests: `tests/sdk_security_overrides/run.py --build-dir .pio/build/esp32-s3-devkitc-1-n16r8`.
+- Build input is the exact-hash original **plus checked-in edits**, not installed source alone. Generated copies replace four target sources without modifying SDK/managed components: HTTPS cleanup/private-key release, HTTPD scratch lifetime/null first read, ESP-TLS server-only protocol list, and wolfSSH password bounds/payload wiping. Original notices and compile properties retained; source/hash/target ambiguity fails configuration. Never hand-edit generated copies or silently repin.
+- Policy/evidence/limits: [library review](../security_library_review.md), [Phase 9C](../security_hardening.md#9c-library-cleanup-and-protocol-policy). Source-contract tests must locate and verify actual generated compilation inputs, not assume original vendor paths.
+
 ## Secure randomness
 
 **Responsibility:** provide the sole project-owned, mutex-serialized application DRBG, seeded before Wi-Fi/radio use.
@@ -71,6 +77,7 @@ This is a semantic map, not a complete file inventory. Start here, then read the
 - Independent throughput diagnostics: `web_serial_transport.{c,h}` owns two fixed per-slot binary-TX aggregates and epoch fences; `web_console.c` exposes default-disabled `web performance enable|disable|show|clear`. Queue-entry/callback-entry, synchronous-send and completion/drain-return estimates, not peer receipt or scheduler-only latency. `tests/web_serial_performance/run.py`; resource/evidence limits and UART0 paired capture: `docs/web_throughput_diagnostics.md`.
 - Storage compatibility: `user_database` persists missing storage empty and preserves valid v1 user bytes; private derived `v1_admin_marker`, no public bootstrap/migration/sync APIs. `web_security` privately migrates v1 1392-byte material to TLS-only v2 1340-byte material, exact identity/generation retained, commit before publish, fail closed without fallback overwrite. Credential commands removed; user generated passwords and TLS rotation remain. Contracts, downgrade and evidence limits: `docs/legacy_credential_removal.md`.
 - Security files: `src/web_security.{h,c}`, `src/web_cookie_auth.{h,c}`, `src/web_session_store.{h,c}`, `src/web_auth_parse.{h,c}`. Private IDF boundary: `src/web_httpd_adapter.{h,c}`.
+- Phase 9C web login: non-consuming early quota/epoch probe before body receive, authoritative reservation after parse; raw JSON wiped before KDF, credentials before error send. Existing verification-count/window/service-restart semantics retained. `tests/web_cookie_auth/run.py --admission` and domain regressions.
 - HTTP policy/UI: `web_cookie_auth` + `web_auth_parse` enforce bounded cookie/Origin/CSRF/admin admission; `web_login_ui.{c,h}` serves login, `web_ui.c` owns session-fenced Serial/Admin/Settings and shared quick controllers. Tests: `tests/web_cookie_auth/run.py` (domain variants), `tests/web_auth_parse/run.py`, `tests/web_login_ui/run.py`, `tests/web_ui_session/run.py`.
 - Admission diagnostics: `web_diagnostics.{c,h}`, `tests/web_diagnostics/run.py`; six post-TLS records/32-event opt-in ring, no HTTPD off-owner inspection. [Contract](../web_admission_diagnostics.md).
 - Identity/lifecycle: `web_server_replace_identity()` + `web_security` reserve service before identity; commit before reserved stop/start, no rollback after commit. `web_lifecycle_settings.{c,h}` owns original-login ID/ACK handoff. Tests: `tests/web_security/run.py`, `tests/web_admin_transport/server_lifecycle.py`.
@@ -111,7 +118,8 @@ Shared UI regression: `tests/web_ui_session/run.py` and its domain `.cjs` fixtur
 
 **Responsibility:** authenticate SSH, route users to serial and administrators to the command dispatcher, and own wolfSSH lifecycle.
 
-- Files: `src/ssh_transport.{h,c}`, `src/ssh_auth_policy.{h,c}`, `src/ssh_security.{h,c}`, `src/ssh_console.{h,c}`
+- Files: `src/ssh_transport.{h,c}`, `src/ssh_auth_policy.{h,c}`, `src/ssh_memory.{h,c}`, `src/ssh_protocol_policy.{h,c}`, `src/ssh_security.{h,c}`, `src/ssh_console.{h,c}`
+- Phase 9C: global wolfSSL hooks securely retire unpoisoned IDF5.5 usable extents (no header; shrink retains capacity, grow can need both blocks). Five checked static-lifetime algorithm setters before context publication. Tests: `tests/ssh_memory/run.py` (optional `--idf-path` extent audit), `tests/ssh_protocol_policy/run.py` (generated feature/KEXINIT/context failure checks).
 - Phase 9B admission: three owner-only boot-lifetime token buckets (handshakes, password/signed-key requests, unsigned probes); no restart/counter-clear reset. Explicit keyboard rejection, pending-result marker and version/feature guard preserve reviewed callback order. Consumed admin RX/accepted TX and retired slots are wiped. Tests: `tests/ssh_auth_policy/run.py`, `tests/ssh_auth_transport/run.py`, `tests/wolfssh_auth_contract/run.py` (requires installed vendor source and production compile database). [Policy/counters/limits](../security_hardening.md#9b-ssh-admission-and-credential-handling).
 - Interfaces: init/start/stop, session snapshots/disconnect/revocation, host-key replacement, counters; `ssh_transport_get_management_snapshot()` / `ssh_transport_manage_current()` fence lifecycle and exact session admission. `ssh_transport_replace_identity()` reserves service before task-bound security identity across stop/commit/restart, retains context until all slots retire and rejects orphan starts. Tests: `tests/ssh_management/run.py`, `tests/ssh_management/security.py`, `tests/ssh_management/runtime.py`.
 - Called by: startup, network clients, user revocation, console/local UI