Remove Legacy Credential Bootstrap Paths

Decouple user provisioning from HTTPS identity storage while retaining
compatible v1 user records and migrating TLS material to the
credential-free
v2 format. Add focused security regression coverage and update operator
documentation.

docs/agent/code-map.md

@@ -65,6 +65,7 @@ This is a semantic map, not a complete file inventory. Start here, then read the
 - Files: `src/web_server.{h,c}`, `src/web_serial_transport.{h,c}`, `src/web_ui.{h,c}`, `src/web_console.{h,c}`
 - Ordinary HTTPS idle cleanup: `src/web_httpd_idle.{c,h}`, owner sweep in `web_httpd_adapter.{c,h}`, lifecycle/TLS composition in `web_server.c`; `tests/web_httpd_idle/run.py`. Independent of diagnostics/optional transports: 15-second observed idle, one-second timer/one queued probe, six rows, actual WS/async/pending exemptions, safe current-owner shutdown and stop/restart fencing. No LRU/socket/timeout/stack increase. SDK queue/owner-delay limits and target checklist: `docs/https_idle_cleanup.md`.
 - Opt-in admission diagnostics: `src/web_diagnostics.{c,h}`, `tests/web_diagnostics/run.py`. Public synchronous HTTPS create/close callbacks publish six post-TLS connection records; four ticket/upgrade wrappers feed a 32-entry numeric ring. UART0/admin SSH `web diagnostics enable|disable|show|clear`; no queue/task/cleanup override or capacity change. Full bounds, SDK semantics and preaccept/TLS blind spots: `docs/phase8d11_implementation.md`.
+- Legacy removal: `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}`.
 - Asset files: authored/generated boundary in `src/web_assets_data.{h,c}`, `web_assets/SOURCES.md`, `web_assets/generate_embedded_assets.py`
 - Interfaces: web init/start/stop/snapshots; HTTP handlers; ticket mint/consume; attach/detach; targeted session revocation
@@ -118,11 +119,11 @@ This is a semantic map, not a complete file inventory. Start here, then read the
 **Responsibility:** persist bounded accounts, verify passwords/SSH keys, issue secret-free principals, and enforce account invariants.
 
 - Files: `src/user_database.{h,c}`, `src/user_console.{h,c}`; `src/admin_command_gate.{h,c}` is currently a narrow recursive wrapper used only by the `user` command handler, not the global command serializer
-- Interfaces: init/migration/recovery, authenticate, principal-currentness, account/password/role/key mutations, snapshots
+- Interfaces: credential-independent init/empty recovery, authenticate, principal-currentness, account/password/role/key mutations, snapshots
 - Called by: web and SSH authentication/currentness checks and console administration
 - Dependencies: NVS, secure random, mbedTLS cryptography; after a committed command-layer mutation, best-effort web/SSH revocation calls supplement authoritative transport currentness checks
 - Ownership: database mutex protects the internal live record and PSRAM-preferred transactional candidate; password authentication runs PBKDF2 outside the mutex and revalidates afterward, while mutation locking must be checked per operation.
-- Authorization: UART0 exclusively owns initial administrator bootstrap and unavailable-database recovery; current admins may use admin SSH for other commands unless handler policy denies them. HTTPS currently treats both roles alike.
+- Authorization: UART0 establishes the first administrator through normal `user add` and exclusively owns unavailable-database recovery to empty (healthy database refused); current admins may use admin SSH for other commands unless handler policy denies them. HTTPS serial/status permits both roles; administration requires `admin`.
 - Constraint: final administrator cannot be deleted or demoted; transport principals must be rechecked after mutations.
 
 ## Administration console infrastructure