Restructure project documentation

Separate operator guides from development contracts, relocate
implementation notes under `docs/devel/`, and update cross-references
and
hardware tooling paths. Add getting-started, user administration, and
firmware update guides while preserving firmware behavior.

docs/agent/design-decisions.md

@@ -6,13 +6,13 @@ Only constraints supported by implementation or current project documentation be
 
 **Decision:** `local_status_ui` owns a nonwrapping configuration generation and a zero-wait reservation shared by typed Display and CLI/legacy Apply. NVS runs outside timing critical sections; Save stabilizes selected bytes and Reset commits defaults before RAM publication. Load retains canonical fallback. Buttons/diagnostic holds update activity, not configuration generation.
 
-**Consequence:** Compare before mutation, never overwrite intervening CLI edits, and do not make physical panel presence a configuration prerequisite. A successful config API is not proof of display IO. [Owner and persistence contract](../web_administration.md#serial-and-display).
+**Consequence:** Compare before mutation, never overwrite intervening CLI edits, and do not make physical panel presence a configuration prerequisite. A successful config API is not proof of display IO. [Owner and persistence contract](../devel/web_administration.md#serial-and-display).
 
 ## Typed Network edits preserve manager ownership and current secret bytes
 
 **Decision:** HTTPD uses zero-wait secret-free projections and an ID-only dispatcher. Wi-Fi compare/merge/whole-candidate validation and queue-before-publication preserve omitted secrets and reject stale changes; its manager alone owns radio/reannouncement. mDNS generation/persistence is independent. Save stabilizes selected RAM; Wi-Fi Load is stored-only, not fallback-secret generation.
 
-**Consequence:** Keep SSIDs reversible bytes, omitted/Replace/disabled-STA Clear distinct, AP clear denied, and Next profile separate from editor selection. mDNS may report RAM applied but reannouncement not queued, without rollback. A one-second queued-secret timer is not hard cancellation; `accepted` is not online/DNS. Recovery and no automatic replay are correctness requirements. [Network contract](../web_administration.md#network).
+**Consequence:** Keep SSIDs reversible bytes, omitted/Replace/disabled-STA Clear distinct, AP clear denied, and Next profile separate from editor selection. mDNS may report RAM applied but reannouncement not queued, without rollback. A one-second queued-secret timer is not hard cancellation; `accepted` is not online/DNS. Recovery and no automatic replay are correctness requirements. [Network contract](../devel/web_administration.md#network).
 
 ## One broker mediates all production serial transports
 
@@ -32,9 +32,9 @@ Only constraints supported by implementation or current project documentation be
 
 **Consequence for future changes:** Do not replace fan-out with a blocking shared queue. Any added transport must tolerate partial/no-progress reads and expose drop/backpressure counters.
 
-**Throughput observation and controlled experiments:** The initial diagnostic baseline used CPU160MHz; a CPU240MHz-only experiment reduced but did not eliminate browser queue overflow. Combining binary WebSocket header/payload into one bounded session-override send eliminated reported drops, and the user signed off230400-baud full-client-mix operation after returning to160MHz. Retain the combined send, not the frequency increase; evidence and limits are in `current-state.md`. Preserve scheduling/priorities and 4096/512-byte broker/web buffers while gathering per-client HWM/drop attribution and independent opt-in web binary-TX timing. Fixed-slot epoch/generation-fenced aggregates avoid stale attribution; no new runtime allocations. Clear preserves queued data and seeds broker HWM; disconnected rows disappear while global discard counts remain. Callback timestamps precede the transport lock; synchronous send return is not peer receipt. Completion-to-read intervals include broker/mutex/control work and possible idle, even when the first read is nonempty; never label them pure scheduling latency or proof of backlog at completion. Compare enabled/disabled target captures before drawing overhead conclusions. Contracts and reproduction: [throughput diagnostics](../web_throughput_diagnostics.md).
+**Throughput observation and controlled experiments:** The initial diagnostic baseline used CPU160MHz; a CPU240MHz-only experiment reduced but did not eliminate browser queue overflow. Combining binary WebSocket header/payload into one bounded session-override send eliminated reported drops, and the user signed off230400-baud full-client-mix operation after returning to160MHz. Retain the combined send, not the frequency increase; evidence and limits are in `current-state.md`. Preserve scheduling/priorities and 4096/512-byte broker/web buffers while gathering per-client HWM/drop attribution and independent opt-in web binary-TX timing. Fixed-slot epoch/generation-fenced aggregates avoid stale attribution; no new runtime allocations. Clear preserves queued data and seeds broker HWM; disconnected rows disappear while global discard counts remain. Callback timestamps precede the transport lock; synchronous send return is not peer receipt. Completion-to-read intervals include broker/mutex/control work and possible idle, even when the first read is nonempty; never label them pure scheduling latency or proof of backlog at completion. Compare enabled/disabled target captures before drawing overhead conclusions. Contracts and reproduction: [throughput diagnostics](../devel/web_throughput_diagnostics.md).
 
-**Relevant files:** `src/session_broker.c`, `src/session_broker.h`, `docs/roadmap.md`
+**Relevant files:** `src/session_broker.c`, `src/session_broker.h`, `docs/devel/roadmap.md`
 
 ## Physical UART ownership and logical writer ownership remain separate
 
@@ -50,13 +50,13 @@ Only constraints supported by implementation or current project documentation be
 
 **Decision:** Broker/SSH/WebSocket slots, originating web sessions, queued admin operations and account principals carry distinct generation/identity fences. Browser cookie-session identity is not interchangeable with account identity. Invalidate session records before socket cleanup and retain authoritative currentness checks even when notifications fail.
 
-**Consequence:** Never turn selected transport IDs into arbitrary broker IDs/fds, rebase a stale confirmation or wrap a published token. Exhausted broker/SSH slots retire; operation/reservation IDs do not reuse; saturated service/lease generations fence ABA without disabling canonical recovery. Reboot invalidates old logins. Validate/reserve at the owner immediately before effects, not snapshot-check/unlock/unconditional mutation. [Broker](../web_administration.md#broker-and-contextual-controls) and [service](../web_administration.md#service-lifecycle-and-identity-rotation) contracts.
+**Consequence:** Never turn selected transport IDs into arbitrary broker IDs/fds, rebase a stale confirmation or wrap a published token. Exhausted broker/SSH slots retire; operation/reservation IDs do not reuse; saturated service/lease generations fence ABA without disabling canonical recovery. Reboot invalidates old logins. Validate/reserve at the owner immediately before effects, not snapshot-check/unlock/unconditional mutation. [Broker](../devel/web_administration.md#broker-and-contextual-controls) and [service](../devel/web_administration.md#service-lifecycle-and-identity-rotation) contracts.
 
 ## Confirmed writer transfer compares a lease version inside the broker lock
 
 **Decision:** Compare the connected nonreused target and separate lease generation inside the force-writer lock. A client ID alone cannot fence release/reacquire ABA. Lease generation saturates, survives counter clear and advances before advisory event delivery, potentially twice for force transfer.
 
-**Consequence:** Saturation rejects typed assignment but preserves ordinary request/release/disconnect and recovery force. Accepted serial TX is not recalled. Live contextual refresh must retain the selected versions and sticky stale/absence state until explicit reselection. [Wrap and UI contract](../web_administration.md#broker-and-contextual-controls).
+**Consequence:** Saturation rejects typed assignment but preserves ordinary request/release/disconnect and recovery force. Accepted serial TX is not recalled. Live contextual refresh must retain the selected versions and sticky stale/absence state until explicit reselection. [Wrap and UI contract](../devel/web_administration.md#broker-and-contextual-controls).
 
 ## UART0 is the physical recovery authority
 
@@ -66,7 +66,7 @@ Only constraints supported by implementation or current project documentation be
 
 **Consequence for future changes:** Network failures or credential corruption must not remove UART0 recovery. Do not expose unauthenticated first-admin provisioning or recovery through web or admin SSH without an explicit security redesign.
 
-**Relevant files:** `src/main.c`, `src/admin_ssh_console.c`, `src/user_console.c`, `docs/roadmap.md`
+**Relevant files:** `src/main.c`, `src/admin_ssh_console.c`, `src/user_console.c`, `docs/devel/roadmap.md`
 
 ## Admin SSH and user SSH are different routes
 
@@ -96,31 +96,31 @@ Only constraints supported by implementation or current project documentation be
 
 **Identity replacement:** Compare/reserve service then task-bound nonreused identity token, shared by canonical/direct callers. Crypto/NVS run outside security locks. HTTPS commits before stop/start; SSH stops before commit/restart. Failed SSH stop skips mutation/start; persistence failure can follow client disconnection. Committed material is never rolled back on restart failure. SSH owner retains context until all slots retire; start rejects orphan handles. Public fingerprint projections do not authorize mutation, and stored/served HTTPS identity can differ after failed stop.
 
-**Consequence:** Explicitly communicate partial effects, trusted UART0 fingerprint verification and fresh HTTPS login after restart. Preserve CLI recovery/reset but do not add browser Reset/export as if it were ordinary rotation. Native USB is independent UART1, not administration or uninterrupted reboot. [Lifecycle/identity contract](../web_administration.md#service-lifecycle-and-identity-rotation).
+**Consequence:** Explicitly communicate partial effects, trusted UART0 fingerprint verification and fresh HTTPS login after restart. Preserve CLI recovery/reset but do not add browser Reset/export as if it were ordinary rotation. Native USB is independent UART1, not administration or uninterrupted reboot. [Lifecycle/identity contract](../devel/web_administration.md#service-lifecycle-and-identity-rotation).
 
 ## Authentication uses copied principals and fail-safe currentness checks
 
 **Decision:** Network sessions retain secret-free copied principals. Database/account ID/auth generation and originating web-session identity must be current at admission, before sensitive input and during reconciliation. Best-effort target notifications supplement, never replace, these checks and cannot roll back committed mutations.
 
-**Consequence:** Shared remote-console slots require transport-qualified tokens and immutable owner adapters. Validate owner currentness outside console locks, then recheck identity. Owner-side HTTPD/SSH IO and generation-safe cleanup remain mandatory; session liveness checks do not cancel executing handlers. Browser-shell permissions are parsed and narrower than typed Settings. [Authentication](../web_administration.md#authentication-and-admission), [console policy](../web_administration.md#browser-shell-policy).
+**Consequence:** Shared remote-console slots require transport-qualified tokens and immutable owner adapters. Validate owner currentness outside console locks, then recheck identity. Owner-side HTTPD/SSH IO and generation-safe cleanup remain mandatory; session liveness checks do not cancel executing handlers. Browser-shell permissions are parsed and narrower than typed Settings. [Authentication](../devel/web_administration.md#authentication-and-admission), [console policy](../devel/web_administration.md#browser-shell-policy).
 
 ## Typed serial mutations share the administration dispatcher
 
 **Decision:** Typed domains queue IDs to the existing serialized dispatcher, never CLI strings or secrets. One original-login slot per domain and a nonreused ID fence stale work; session/deadline checks precede canonical admission. Results are replaceable observations, not durable history/idempotency.
 
-**Consequence:** No automatic mutation replay, including after navigation, timeout or logout. Ordinary deadlines limit dequeue admission, not execution. Accounts/Network queued-secret timers wipe only non-executing inputs; locals wipe after admitted work returns. Explicit RAM/NVS/reset semantics and partial-effect uncertainty must match each canonical owner. [API bounds and lifetime](../web_administration.md#typed-settings-api-and-operation-lifetime).
+**Consequence:** No automatic mutation replay, including after navigation, timeout or logout. Ordinary deadlines limit dequeue admission, not execution. Accounts/Network queued-secret timers wipe only non-executing inputs; locals wipe after admitted work returns. Explicit RAM/NVS/reset semantics and partial-effect uncertainty must match each canonical owner. [API bounds and lifetime](../devel/web_administration.md#typed-settings-api-and-operation-lifetime).
 
 ## Typed account selection is checked inside the database mutation lock
 
 **Decision:** Target username/account ID/auth generation compare occurs inside the canonical mutation lock for role/delete/password/key changes. HTTPD uses compact zero-wait secret-free projections, not the blocking CLI snapshot. Successful changes notify only the target's web/SSH sessions, including self.
 
-**Consequence:** Separate generated-value delivery from mutation and retain no retrieval history; context-bound saved acknowledgement is UX, not receipt proof. Self-revocation can deny results, so 401/disconnect cannot mean success or cancellation. Key slots are stable and sparse, fingerprint-only on output; import shares canonical validation. Final-admin invariants and UART0 provisioning/recovery remain. [Accounts contract](../web_administration.md#accounts-and-authorized-keys).
+**Consequence:** Separate generated-value delivery from mutation and retain no retrieval history; context-bound saved acknowledgement is UX, not receipt proof. Self-revocation can deny results, so 401/disconnect cannot mean success or cancellation. Key slots are stable and sparse, fingerprint-only on output; import shares canonical validation. Final-admin invariants and UART0 provisioning/recovery remain. [Accounts contract](../devel/web_administration.md#accounts-and-authorized-keys).
 
 ## Browser authentication has a narrow version-pinned HTTPD boundary
 
 **Decision:** `web_httpd_adapter` alone accesses private IDF 5.5.0 parsed-header/session state. Reject duplicate/ambiguous headers; defer 101 until cookie/Origin/ticket/transport admission; wipe consumed scratch while preserving unread bytes. Stage optional Settings descriptor/name allocations before publication. Compile header/ticket debug logging out.
 
-**Consequence:** Re-audit SDK assumptions on upgrade; never patch around Origin `null` by weakening same-origin policy. Browser authentication POST uses CORS mode with fixed same-origin URLs/credentials because no-referrer non-CORS POST can serialize Origin as null. Digest-only cookie/challenge sessions replace Basic without fallback or live-record eviction. CSP loader hashes and authored scripts change atomically. Navigation preserves terminals/lease, while session-identity changes require a clean document before showing retained buffers. [Authentication and terminal contracts](../web_administration.md#authentication-and-admission).
+**Consequence:** Re-audit SDK assumptions on upgrade; never patch around Origin `null` by weakening same-origin policy. Browser authentication POST uses CORS mode with fixed same-origin URLs/credentials because no-referrer non-CORS POST can serialize Origin as null. Digest-only cookie/challenge sessions replace Basic without fallback or live-record eviction. CSP loader hashes and authored scripts change atomically. Navigation preserves terminals/lease, while session-identity changes require a clean document before showing retained buffers. [Authentication and terminal contracts](../devel/web_administration.md#authentication-and-admission).
 
 ## Security material and configuration use bounded, versioned NVS records
 
@@ -128,7 +128,7 @@ Only constraints supported by implementation or current project documentation be
 
 **Rationale/evidence:** Serial, Wi-Fi, local UI, web security, users, and SSH security each validate schema/size and own their namespace. User/security mutations build and validate candidate state before committing it; security modules avoid silently replacing an established identity. The live user database remains internal while its 5,360-byte candidate is a persistent PSRAM-preferred allocation with internal fallback and is wiped after every transaction.
 
-**Consequence for future changes:** Add schema versions and transactional candidate validation. Do not overwrite unknown records automatically; provide explicit migration/reset behavior. Preserve the distinct persistence contracts: explicit save/load/default/reset for working configuration and per-blob commit-before-live-install for user and identity mutation. Keep candidate ownership mutex-local and wipe/free it on initialization or recovery failure. Recheck external-buffer staging in the flash/NVS implementation when upgrading from the pinned ESP-IDF 5.5 baseline. Legacy credential synchronization and reconciliation are removed. Missing user storage commits empty; valid user v1 bytes remain compatible, with private `v1_admin_marker` derived from admin count, not a public bootstrap contract. HTTPS v1 (1,392 bytes) migrates through a private validated reader to TLS-only v2 (1,340 bytes), preserving exact DER/fingerprint/generation and committing before publication. Failures fail closed without fallback regeneration or overwriting rejected records. See [legacy compatibility](../roadmap.md#phase8-legacy-credential-compatibility).
+**Consequence for future changes:** Add schema versions and transactional candidate validation. Do not overwrite unknown records automatically; provide explicit migration/reset behavior. Preserve the distinct persistence contracts: explicit save/load/default/reset for working configuration and per-blob commit-before-live-install for user and identity mutation. Keep candidate ownership mutex-local and wipe/free it on initialization or recovery failure. Recheck external-buffer staging in the flash/NVS implementation when upgrading from the pinned ESP-IDF 5.5 baseline. Legacy credential synchronization and reconciliation are removed. Missing user storage commits empty; valid user v1 bytes remain compatible, with private `v1_admin_marker` derived from admin count, not a public bootstrap contract. HTTPS v1 (1,392 bytes) migrates through a private validated reader to TLS-only v2 (1,340 bytes), preserving exact DER/fingerprint/generation and committing before publication. Failures fail closed without fallback regeneration or overwriting rejected records. See [legacy compatibility](../devel/roadmap.md#phase8-legacy-credential-compatibility).
 
 **Relevant files:** `src/serial_config.c`, `src/wifi_config.c`, `src/mdns_config.c`, `src/mdns_service.c`, `src/local_ui_config.c`, `src/web_security.c`, `src/user_database.c`, `src/ssh_security.c`
 
@@ -180,7 +180,7 @@ Only constraints supported by implementation or current project documentation be
 
 **Consequence for future changes:** Do not remove these definitions as a performance cleanup. Any re-enablement needs target-hardware concurrency testing with simultaneous USB, WebSocket, SSH, and serial traffic plus watchdog/stack telemetry.
 
-**Relevant files:** `CMakeLists.txt`, `src/CMakeLists.txt`, `docs/roadmap.md`, relevant `sdkconfig.defaults` crypto settings
+**Relevant files:** `CMakeLists.txt`, `src/CMakeLists.txt`, `docs/devel/roadmap.md`, relevant `sdkconfig.defaults` crypto settings
 
 ## Embedded web assets are checked-in generated artifacts