Add typed serial settings operations

Route bounded admin mutations through the existing administration
dispatcher,
covering apply, lifecycle, persistence, authorization, and result
tracking.
Add the browser controls, automatic result refresh, regression coverage,
and
phase documentation.

docs/agent/current-state.md

@@ -4,6 +4,12 @@ This file is working memory. Update it during active work and before handoff; do
 
 ## Development state
 
+- **8D.9 UX refinement (2026-09-08), host-tested/build-verified; target pending:** User reported successful Apply required awkward manual Check Result then Refresh and approved automatic flow/removing routine popups. `web_ui.c` now keeps settings visible/stale while pending, checks acknowledged operations every 1 s up to 10 GET attempts/15 s overall, then refreshes working values while preserving outcome. Errors/exhaustion/lost ack use manual recovery; no POST retry, no resume after navigation. Only Reset retains a saved-NVS overwrite confirmation; inline discard semantics remain. Current-view selection is a no-op so repeated Settings clicks cannot cancel work. Parent UI **35 groups + renderer/CSP**, `pio run` **10.91 s / 95,708 B RAM / 1,668,837 B flash**, diff check PASS; **0 / +2,112 B** vs original 8D.9. No backend/assets/device/commit action or new signoff. Details/evidence limits in `docs/phase8d9_implementation.md`; target automatic-completion, failure/manual-recovery and full-mix latency checks pending.
+
+- **8D.9 continuation complete (2026-09-07), implemented / reviewed / host-tested / build-verified; target/signoff pending:** Preserved inherited implementation; typed Apply/Start/Stop/Save/Load/Defaults/Reset uses one session-bound slot and the existing dispatcher queue, 256-byte JSON POST and 96-byte explicit GET results. No new tasks/stacks/queue depth or broker lease semantics; 19 URI handlers, six sockets/no LRU. Fixed persistent uncertain-result warnings and consistent zero-wait `/api/status` serial state (`running:null` when unavailable). Final parent Serial 10, Settings/status 6, UI 27/CSP, console boundary and lifecycle 13 groups pass; additional transport/tickets/store/admin/account/lifecycle regressions passed during review. Final `pio run` 23.73 s, **95,708 B RAM / 1,666,725 B flash**, **+128 / +12,196 B** vs 8D.8. Deadline is dequeue admission only; blocked dispatcher retains pending slot, admitted NVS work may finish after logout, completed results can be replaced. Exact contracts/tests/limits and pending target checklist: `docs/phase8d9_implementation.md`. No target/device/asset/commit action, reserve approval or 8D.8/8D.9 signoff. Stop before separately requested 8D.10; M2 acceptance and existing deferred restrictions/admission followups stand.
+
+- **8D.9 original handoff (2026-09-07; superseded by completion above):** User explicitly requests end-to-end Serial typed edits/persistence despite pending 8D.8 target validation. This is continuation authorization, not 8D.8 target signoff. Plan: verify canonical serial and concurrency contracts; implement a single bounded session-bound operation slot on the existing dispatcher with nonblocking HTTP admission/result reads; add explicit Serial controls and focused regressions; finite build, diff review and accurate resource/target handoff. No later domains/popovers/generated assets/device/commit actions. Existing modification to `docs/phase8d8_implementation.md` belongs to parent/user and is preserved. M2 acceptance, deferred restrictions, unresolved admission and unapproved memory/stack followups stand.
+
 - **8D.8 separately authorized, implemented / host-tested / build-verified (2026-09-07), target/signoff pending:** Admin-only Settings/Serial in the existing document, bodyless server-authorized `GET /api/settings/serial`, eight typed working values with 256-byte response bound. Nonblocking serial-state snapshot avoids blocking HTTPD on console reconfiguration; no mutations/NVS/broker/terminal lifecycle side effects. Selection preserves both sockets/lease and hidden output; explicit refresh, safe errors, cancellation/identity/expiry and concurrent-reconnect fencing. One optional URI (17 total), six sockets/no LRU unchanged. Private IDF adapter stages new-route descriptor/name before publication to avoid installed public registration's dangling entry on strdup failure; only the new Settings route uses it, broader inherited registration audit remains a followup. Final `pio run` **24.31 s, 95,580 B RAM / 1,654,529 B flash**, **0 / +5,952 B** vs recorded 8D.7; **+1,048 / +54,556 B** vs 8D.0. Target snapshot/descriptor 36/24 B; requested route/table heap +49 B before overhead, handler local frame 416 B excluding callees, no stack/task/queue/capacity increase. UI **21**, Settings **5**, lifecycle **12**, transport **25**/tickets **12** and auth/store/login/parser/console/policy regressions pass; diff check passes. No device, sanitizer, generated-asset or commit action; inline loader/CSP hashes unchanged and verified. Task/todowrite tools unavailable; implementer review fixes rerun, no independent-agent review claim. See `docs/phase8d8_implementation.md` for exact tests/resources/limits/pending target checklist. **M2 signoff, deferred restrictions, accepted unresolved admission issue and unapproved memory/stack followups stand. Stop before separately requested 8D.9; no new-phase signoff inferred.** This supersedes the older next-8D.8/wait-for-request instructions below, not their signoff/evidence.
 
 - **M2 explicitly signed off by the user (2026-09-07):** After 8D.7 implemented-scope validation and discussion of read-only settings next, the user says "Jupp, sign M2 off". This supersedes all earlier M2-open statements and continuation instructions below; accepted M2 does not require revalidation or imply full browser command parity. Browser self-target/generated-password/key/legacy-credential and other owner-specific command restrictions remain deferred; bootstrap/recovery remain permanently UART0-only. Intermittent supported two serial + one admin web admission failures are accepted nonblocking, not fixed or diagnosed. Numeric memory reserves and stack margins remain unapproved follow-ups, not blockers reopening M2. **Next: 8D.8 read-only settings entry and Serial page, only when separately requested; this sign-off alone authorizes no implementation.** Evidence/history: `docs/phase8d7_implementation.md`. Documentation only; no source/tests/build/device/commit action.