Add Typed SSH Service Controls

Provide admin-only SSH status plus generation-safe start, stop, and
single-session disconnect operations through the bounded dispatcher.
Include
Settings UI coverage, lifecycle safeguards, and host-side regression
tests.

docs/agent/current-state.md

@@ -4,6 +4,8 @@ This file is working memory. Update it during active work and before handoff; do
 
 ## Development state
 
+- **8D.19 first service slice — SSH (2026-09-13), user-authorized; implemented/host/build verified, independently reviewed; target sign-off pending:** Admin Settings/SSH provides safe two-row status and confirmed SSH start/stop/one-session disconnect only. `web_ssh_settings` owns256-byte/four-receive request,768-byte snapshot,96-byte result and one login-bound slot/30-second dequeue deadline; existing four-entry dispatcher receives IDs only. SSH owns zero-wait published snapshot, command-mutex conditional lifecycle admission with saturated service generation (CLI stop/start ABA included), exact-ID external close and retired exhausted session slots. HTTPD never waits for SSH/wolfSSH; no new task/timer/stack/depth/socket/asset/config/dependency.36 handlers/six sockets. UI uses existing Settings styles/native confirmations, sticky stale target selection,15-second whole-request deadline and explicit manual Check Result then Refresh (no polling/replay). Invoking HTTPS login/browser terminals/Wi-Fi/USB/UART0 are not stopped. Canonical browser-shell restrictions unchanged. All web-session/HTTPS/USB actions excluded; other-service8D.19 requires separate owner/scope audit, phase incomplete; no8D.20/21. Initial worktree clean. PASS canonical SSH4, cookie SSH6+shared/all existing variants, dispatcher, lifecycle27, UI143+six-view HTML/CSP, broad accounts/Network/broker/policy/auth/transport/store/idle/diagnostics/performance/security/login and diff check. Independent reviewer found no confirmed actionable defects; canonical SSH4, cookie SSH6+shared, dispatcher, lifecycle27, UI143+renderer/HTML/CSP and diff checks independently PASS. Parent final pio confirmation PASS19.95s100,404/1,808,441 B; diff check PASS. Baseline pio6.87s100,300 RAM/1,793,301 flash; final35.31s100,404/1,808,441 (+104/+15,140 B). CPU160 defaults/active/generated confirmed;8D.18 contexts/combined binary WS path preserved. No hardware/real-browser geometry/heap/stack validation, upload/erase/commit or target/reserve/M3 sign-off. Exact API/owner race/uncertainty/resource/test limits and pending checks: `docs/phase8d19_implementation.md`.
+
 - **8D.18 implemented (2026-09-13), user-authorized; host/build verified, independently reviewed; target sign-off pending:** UI-only Broker clients/Active writer contexts reuse8D.16 snapshot/lease fence/operation controller and8D.17 single host/native confirmation/dismissal focus fix.5-second-after-success single-flight live refresh with5-second whole-read deadline; errors/timeouts stop, no auto error/mutation retry. Explicit selection identity+lease token is never rebased; stale/absent latches prevent resurrection, consumed selection requires explicit reselection. New triggers preserve full-page Serial/account/Network drafts even on activation; quick promotion preserves selection/controller and stops live timer. Focused controls use aria-disabled plus existing handler guards rather than native focus loss; previous terminals keep receiving with input isolated. Initial worktree clean. PASS135 UI groups+renderer/HTML/CSP, broker management/wrap, cookie Broker+base/all existing variants, lifecycle25, dispatcher/canonical accounts/Network, parser294, transports/tickets/store, idle/diagnostics/performance/security/login and diff check. Broad tests preceded final focus refinement; full UI/build rerun afterward. Independent reviewer found no confirmed actionable defects and reran UI135+renderer/HTML/CSP, canonical broker management/wrap, cookie Broker and diff checks PASS. Parent final pio confirmation PASS6.89s100,300/1,793,301 B; diff check PASS. Native picker during live updates and actual blank/reselect remain browser-validation gaps, not proven defects. Baseline pio7.02s100,300 RAM/1,788,661 flash; final21.52s100,300/1,793,301 (+0/+4,640 B). CPU160 defaults/active/generated verified, combined WS send unchanged. No backend/API/policy/assets/config/dependencies/icons/8D.15/19/later/upload/erase/commit/SDK changes. No real-browser geometry/accessibility or device tests this phase; no reserve/M3 claim. Exact contract, test-development corrections and pending parent/target checklist: `docs/phase8d18_implementation.md`. Stop before any separately authorized next phase.
 
 - **8D.17 independent-review P2 fixed (2026-09-13), independently confirmed resolved:** Quick dismissal now restores Serial/Admin state/input without xterm focus; automatic departure and adjacent-trigger switches preserve focus, Escape/Close focus only trigger. Observable Terminal.focus harness reproduced adjacent-trigger failure before fix;128 UI groups+renderer/HTML/CSP PASS, pio21.90s100,300 RAM/1,788,661 flash (+0/+32 B review delta; phase+0/+6,048 B), diff check PASS. Two new groups cover adjacent keyboard triggers and timed/outside-pointer dismissal/explicit focus for both terminal backgrounds. Existing uncommitted work preserved; no unrelated source/device/assets changes. Reviewer confirmed no new actionable findings and independently reran128 UI groups+renderer/HTML/CSP and diff checks PASS. Parent final build confirmation PASS6.98s,100,300/1,788,661 B; diff check PASS. Exact correction in `docs/phase8d17_implementation.md`; target/geometry limits remain.