Implement SSH authorized key management

docs/agent/architecture.md

@@ -154,6 +154,8 @@ NVS is not encrypted. Password verifiers improve password storage, but Wi-Fi cre
 
 ## Typed Accounts settings (8D.10)
 
+**8D.11 extension:** Authorized-key operations share the Accounts slot/dispatcher and canonical database key transactions with mutation-lock account ID/generation checks. A zero-wait per-account projection returns only key slot/type/SHA256 fingerprint. Independently optional admin/Origin/CSRF JSON POST `/api/settings/accounts/keys` reads this projection; existing operation POST admits bounded public-key text or key-delete/key-clear. Three stable slots may be sparse. Successful mutations target-revoke, including self; uncertain acknowledgement never triggers automatic replay. 24 handlers, unchanged socket/task/stack-size/queue budgets. Runtime stack margins remain pending. See `docs/phase8d11_implementation.md`; older no-8D.11 statements below are historical.
+
 Current slice 2 extends the same dispatcher slot to create/password and self role/delete/password. Mutation bodies are 768 bytes/four receives; results stay secret-free, 96 bytes, replaceable and session-bound. Conditional password mutation checks identity under the canonical database mutex. A one-second firmware-lifetime ESP timer cancels/wipes non-executing queued credentials at their 30-second deadline plus timer/scheduling latency; dequeue wipes shared inputs after copying, and dispatcher-local credentials persist until admitted work returns. This is not a hard execution/erasure deadline. Separate bodyless admin/Origin/CSRF POST `/api/settings/accounts/generate-password` returns a 24-character value before any commit, without retained retrieval. UI generation has a 60-second best-effort lifetime and context-bound saved acknowledgement before separate submission; JavaScript cannot securely wipe strings. Self revocation may prevent final response/result access; disconnect/401 proves neither success nor cancellation. Browser-shell restrictions and UART0-only bootstrap/recovery remain unchanged. The generated endpoint is independently optionally registered, with failure isolation/restart coverage and 23 handlers. Implementation is complete, host-tested/build-verified; target validation/signoff remains pending. Parent build: 25.61 s, 95,908 B RAM / 1,694,237 B flash; timer runtime costs and stack/heap margins remain unmeasured. No task/stack/queue depth/socket expansion or 8D.11 work. Current contracts and attributed host evidence: `docs/phase8d10_implementation.md`.
 
 **Historical slice 1 architecture (superseded scope/counts, retained evidence):**

docs/agent/code-map.md

@@ -58,6 +58,8 @@ This is a semantic map, not a complete file inventory. Start here, then read the
 
 ## Web and WebSocket serial
 
+- **8D.11:** `web_account_settings.{c,h}` extends Accounts with fingerprint-only POST `/api/settings/accounts/keys` and key-add/key-delete/key-clear on the existing operation endpoint/dispatcher. `user_database.{c,h}` owns zero-wait target-checked snapshots and canonical conditional key mutations. `web_ui.c` handles confirmations, sparse stable indices and self-revocation uncertainty. 24 handlers, six sockets; no new task/stack/queue depth. Host-tested/build-verified, target pending. Contracts/tests/checklist: `docs/phase8d11_implementation.md`.
+
 **Responsibility:** serve authenticated HTTPS UI/API, issue WebSocket tickets, and adapt browser serial sessions to broker clients.
 
 - Files: `src/web_server.{h,c}`, `src/web_serial_transport.{h,c}`, `src/web_ui.{h,c}`, `src/web_console.{h,c}`

docs/agent/current-state.md

@@ -4,6 +4,10 @@ This file is working memory. Update it during active work and before handoff; do
 
 ## Development state
 
+- **8D.11 partial target evidence (2026-09-08):** User supplied 60-second fresh-boot/full-mix telemetry; no functional/sign-off claim. Full mix eventually established (two SSH public-key sessions, SSH writer + USB/two web observers, both admins), but last browser admission again required retries. Three TLS errors `-0x0050` verified against installed mbedTLS as NET_CONN_RESET, not allocation failure; cause unknown. Loaded internal/DMA free 32,596/24,840 B, lifetime minima 5,468/532 B, largest 22,528 B; per-region minima are conservative/non-simultaneous. Settled free is similar to prior 8D.10, minima much lower; no causal regression attribution. SSH stack minimum-free 18,468 boot/16,276 loaded B. Web send failure/close 1, expired tickets 3; SSH handshake/auth failures zero; no broker drop counters. Exact memory/counters/evidence limits in `docs/phase8d11_implementation.md`. Previously accepted admission issue recurred, not fixed; investigate timing/socket occupancy/allocation correlation before capacity changes. Key algorithms/new UI provenance, mutation checklist, HTTPD/dispatcher margins, cleanup/soak and target sign-off remain pending. Documentation-only update; no source/build/device action.
+
+- **8D.11 implemented (2026-09-08), host-tested/build-verified; target sign-off pending:** Accounts now supports fingerprint listing and bounded Ed25519/P256 public-key import/delete/clear. Conditional database wrappers check target identity under the canonical lock; existing dispatcher/account slot and target-only revocation remain. Optional POST `/api/settings/accounts/keys` brings handler budget to 24, six sockets/tasks/stacks/queue depth unchanged. Sparse stable key slots are supported; review finding fixed and regressed. Parent canonical accounts, cookie accounts, UI, lifecycle (16), build and diff checks passed; final agent UI extension passes 68 groups plus CSP. Final production build 14.85 s, 96,076 B RAM / 1,703,685 B flash (+168/+9,448 vs 8D.10). Exact API, evidence attribution and pending target checklist: `docs/phase8d11_implementation.md`. No device/assets/commit action, reserve approval, full M3 claim or 8D.12 work. Supersedes the older wait-for-8D.11 instruction below, not accepted 8D.8–8D.10/M2.
+
 - **8D.8–8D.10 implemented scope signed off by user (2026-09-08):** User provides settled boot/full-mix telemetry and reports thorough Serial parameter display/settings and user/account testing: “Implemented work can be signed off.” Accepts 8D.8, 8D.9 including UX refinement, and both implemented 8D.10 slices, superseding pending-signoff/target-blocker statements below without inventing individual checklist passes. Current source/handoff confirms credential/self workflows and generated route complete. Exact flashed revision/browser/durations/reboot/fault-injection details not separately supplied. Full mix at **230400 8N1 RTS/CTS, DTR active**: SSH writer8, USB observer9, web observers26/11, SSH admin and web admin, two cookie sessions; no broker drop counters supplied. Boot internal/DMA/PSRAM free **69,928/62,172/8,246,368 B**, loaded final **32,556/24,800/8,087,656 B**, loaded minima **19,228/11,472/8,065,444 B**, largest **23,552/23,552/7,995,392 B**. SSH minimum-free stack **18,476 boot / 16,284 loaded B**. One SSH handshake failure/broker revocation, one WebSocket send failure/close and one invalid login retained without diagnosis. All six loaded samples, counters, scope and evidence limits: `docs/phase8d10_implementation.md`. Numeric reserves, HTTPD/dispatcher stack margins, cleanup/soak evidence and earlier accepted admission issue remain followups, not reopening sign-off. Browser-shell restrictions/UART0 recovery and M2 stand; no full M3 claim. **Wait for separately requested 8D.11.** This update documentation-only, no new build/test/device/source/config/asset/commit action; preserve existing user `platformio.ini` edit.
 
 The following implementation entries predate target sign-off and retain historical build/test attribution; their target-pending status is superseded above.

docs/agent/design-decisions.md

@@ -108,6 +108,8 @@ Phase 8D.4 routes drain/lifecycle operations through a firmware-lifetime immutab
 
 ## Typed account selection is checked inside the database mutation lock
 
+**8D.11:** Apply the same conditional target identity contract to authorized-key add/delete/clear, sharing canonical CLI validation/commit paths. Expose fingerprint metadata only through a zero-wait snapshot; never return stored key blobs. Treat key indices as stable, potentially sparse slots, not response-array positions. Listing uses protected JSON POST to reuse bounded target admission, not a new query parser. Public-key import is bounded to 384 decoded text bytes within the existing 768-byte body, with canonical blob/curve validation on the existing dispatcher. Target revocation/self uncertainty and browser-shell restrictions are unchanged. See `docs/phase8d11_implementation.md`.
+
 **Current 8D.10 slice 2:** Extend conditional identity checks to password replacement; create uses canonical duplicate/capacity/commit policy. Keep generation separate from commit: the protected bodyless generated-value POST returns one transient value, performs no mutation and retains no retrieval state. Browser saved acknowledgement is context-bound UX, not delivery proof or server authorization. Queued credentials require a one-second periodic timer to cancel/wipe non-executing work at the 30-second deadline plus scheduling latency; execution copies then wipes shared inputs, with local wiping after admitted database work returns. Neither timer nor logout cancels admitted commits. Self password/role/delete uses immediate canonical target revocation, not deferred acknowledgement: 401/disconnect is uncertain and requires relogin/inspection before any explicit retry. Generation is independently optionally registered, preserving failure isolation and restart behavior at 23 handlers. No shell restriction change, secret result/history, new executor or 8D.11 work. Implementation is complete, host-tested/build-verified, not target accepted; timer runtime costs remain unmeasured. See contracts, build and attributed test evidence in `docs/phase8d10_implementation.md`.
 
 The following first-slice exclusions are historical and superseded by slice 2: