Pr1 nodedb warmstore (#10705)

* NodeDB: 3-tier node store with persistent warm tier (long-tail identity retention)

Introduces a tiered NodeDB so the device retains identity (public key,
last_heard) for far more nodes than fit in the full-record hot store,
without growing heap or the persisted nodes.proto unboundedly.

- Hot store: full NodeInfoLite, MAX_NUM_NODES (120 on nRF52).
- Satellite maps: position/telemetry/environment/status capped at
  MAX_SATELLITE_NODES (40 freshest); eviction via enforceSatelliteCaps /
  evictSatelliteOverCap.
- Warm tier (WarmNodeStore): 40 B {num,last_heard,public_key} records for
  evicted nodes so DMs to/from long-tail nodes keep encrypting/decrypting.
  Persisted to /prefs/warm.dat, or on nRF52840 a dedicated 12 KB raw-flash
  record-ring below LittleFS (3x4 KB pages; see linker scripts + the
  nrf52_warm_region.py post-link guard).

NodeDB::getOrCreateMeshNode now demotes evicted nodes into the warm tier and
re-admits them (restoring key/last_heard). Router PKI decrypt/encode resolve
the peer key via NodeDB::copyPublicKey (hot store, then warm tier).

NodeInfoLite gains snr_q4 (sint32, Q4-encoded dB); the float snr is zeroed on
disk. NodeInfoLite grows 105 -> 112 B; backup 2432 -> 2468 B.

Note: the snr_q4 .proto change still needs to land in the protobufs submodule
(generated header is updated here; submodule pointer left at upstream).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* NodeDB: robust receive + retention for blocked (ignored) nodes

Hardens how ignored/favourite nodes are received over admin and retained,
closing paths where a block could be lost or accidentally cleared.

- Blocking keeps the node's public key (admin set_ignored_node and
  addFromContact no longer zero it / drop the warm-tier key), so a blocked
  peer stays a verifiable identity.
- set_ignored_node creates the node if absent, so a block by node ID sticks
  even for a node we've never heard from (e.g. pushed by a remote admin) with
  no NodeInfo or key.
- Eviction protection (favourite/ignored/manually-verified) now also applies to
  the load-time hot-store migration and is never undone by cleanupMeshDB, which
  previously purged ignored nodes that lacked user info.
- The hot-store migration leaves our own node (index 0) in place and prefers to
  demote non-protected nodes, like the runtime eviction scan.

Caps the protected set (favourite + ignored + verified) at MAX_NUM_NODES-2 via
NodeDB::setProtectedFlag(), so at least two evictable slots always remain and
getOrCreateMeshNode can always make room — replacing the previous unconditional
append that could run off the end of the node vector when every node was
protected. A locally-set favourite/ignore that hits the cap reports back to the
phone via a ClientNotification.

Adds test_nodedb_blocked covering the migration, favourite/ignored eviction
protection, ignored-survives-cleanup, and the protected-node cap. The
maintenance methods stay private in production; the test reaches them through a
PIO_UNIT_TESTING-guarded friend shim.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

# Conflicts:
#	src/mesh/NodeDB.h

* fix copilot comments

* once again

* WarmNodeStore: fix cppcheck warnings (uninitvar, constVariablePointer)

Zero-initialise `stranded[]` and `seqs[]/order[]` VLAs so cppcheck can
verify there are no unguarded reads of uninitialised memory (the guards
exist but are not visible to static analysis). Mark two local pointers
`const` where the pointed-to entry is never mutated after assignment.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* self-care added to assist 2.7 and 2.8 nodedb migration

* Tidy warm-store/self-care: comments, guards, log + flash cleanup

Style/cleanup pass over the branch (no behavior change except the noted
preprocessor simplifications, which are semantically identical):

- Comments: move function descriptions to the headers, cap in-function
  comments at ~3-4 lines, drop leading-number step markers, label stacked
  #endif blocks, de-decorate banner comments.
- dumpToLog: fully gate decl + definition + AdminModule call site behind
  MESHTASTIC_NODEDB_MIGRATION_VERBOSE so it compiles out when disabled
  (~1.2 KB when off).
- mesh-pb-constants: drop the dead nRF52832 WARM_NODE_COUNT branch and trim
  the macro docs.
- WarmNodeStore: simplify the redundant `ARCH_NRF52 && NRF52840_XXAA` guards
  to `NRF52840_XXAA`, add a kNoPage sentinel for the ring page state.
- Shorten the always-on LOG_WARN strings (~120 B flash).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* more tidying up, aligning with docs and undoing other-arch regressions

* Update protobufs (#19)

Co-authored-by: NomDeTom <116762865+NomDeTom@users.noreply.github.com>

* made the migration pathway cleareer

* address copilot review

* fixed a copilot review on a downstream PR.

* Address Copilot review comments for PR #10705 (warmstore/nodedb)

- WarmNodeStore.h: default MIGRATION_VERBOSE to 0 (suppress info-level
  chatter on production builds; opt in with =1)
- WarmNodeStore.cpp load(): move memset to top of function so all
  failure paths (header-read fail, invalid header) leave entries clear
- WarmNodeStore.cpp save(): replace manual spiLock lock/unlock around
  mkdir with LockGuard covering the full SafeFile sequence, matching
  the lock discipline in load()
- Router.cpp: memcpy(&p->public_key.bytes, ...) -> memcpy(p->public_key.bytes,
  ...) — pass decayed uint8_t* rather than pointer-to-array
- AdminModule.cpp: check setProtectedFlag return for PKC auto-favorite;
  log cap-refusal warning instead of unconditional "auto-favoriting"
- nrf52_warm_region.py: error message references both v6.ld and v7.ld

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* NodeDB: formatting cleanup (blank lines after preprocessor blocks)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* Lukewarm store

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

.github/copilot-instructions.md

@@ -191,7 +191,24 @@ Writers go through `setNodeStatus`, `updatePosition`, `updateTelemetry` (which d
 
 ### Eviction
 
-Every code path that drops a node from the header table must also evict the satellites. The single chokepoint is `eraseNodeSatellites(NodeNum)`; it's already called from `getOrCreateMeshNode`'s oldest-boring eviction, `removeNodeByNum`, both branches of `resetNodes`, `cleanupMeshDB`, `addFromContact`'s ignored-branch, and `AdminModule`'s `set_ignored_node`. Add new eviction sites here, not by calling `.erase()` directly.
+Every code path that drops a node from the header table must also evict the satellites. The single chokepoint is `eraseNodeSatellites(NodeNum)`; it's already called from `getOrCreateMeshNode`'s oldest-boring eviction, `demoteOldestHotNodesToWarm` (the over-cap warm-tier migration), `removeNodeByNum`, both branches of `resetNodes`, `cleanupMeshDB`, `addFromContact`'s ignored-branch, and `AdminModule`'s `set_ignored_node`. Add new eviction sites here, not by calling `.erase()` directly. (Note: `enforceSatelliteCaps`/`evictSatelliteOverCap` call `.erase()` directly on purpose — that's a satellite-only cap trim where the node _stays_ in the header, a different operation from this chokepoint.)
+
+### Warm tier (long-tail identity)
+
+On every arch except STM32WL and bare nRF52832 (`WARM_NODE_COUNT > 0`), a node evicted from the header table is not forgotten outright: `WarmNodeStore` (`src/mesh/WarmNodeStore.{h,cpp}`) keeps a 40 B `{num, last_heard, public_key}` record per evicted node — primarily so PKI DMs to/from a long-tail node keep decrypting without re-running a NodeInfo exchange (the rest of `NodeInfoLite` rebuilds from traffic in seconds).
+
+- **Write:** `getOrCreateMeshNode`'s eviction and `demoteOldestHotNodesToWarm` (the over-cap boot migration) call `warmStore.absorb(num, last_heard, key)` _before_ the node leaves the header.
+- **Read-back:** `getOrCreateMeshNode` calls `warmStore.take()` to rehydrate `last_heard` + key when a warm node is re-admitted; `copyPublicKey()` falls back to the warm tier so the PKI send path finds keys for evicted peers.
+- **Persistence:** nRF52840 uses a 12 KB raw-flash record-ring at `0xEA000` (below LittleFS; append + replay + compact-on-rotate, link-guarded by `nrf52840_s140_v7.ld` and `extra_scripts/nrf52_warm_region.py`). Everywhere else: a `/prefs/warm.dat` snapshot flushed by `saveIfDirty()` on the node-DB save cadence.
+- **Tunables** (`mesh-pb-constants.h`): `WARM_NODE_COUNT` (per-arch; `0` disables the tier) and `MAX_NUM_NODES` (hot cap — 120 on nRF52840/generic ESP32 to fit the 28 KB LittleFS; ESP32-S3 keeps its flash-scaled 100/200/250, portduino 250). Verbose migration/self-care tracing routes through `LOG_MIGRATION`, gated by `MESHTASTIC_NODEDB_MIGRATION_VERBOSE`.
+
+### Satellite caps
+
+Only the freshest `MAX_SATELLITE_NODES` nodes keep satellite payloads; the rest of the header table carries just the `NodeInfoLite`. The cap is **per-platform**: 40 on RAM-constrained parts (nRF52840, generic ESP32) since the four maps live in internal SRAM (not PSRAM, ~408 B/node across the four), and 250 on flash-rich hosts (ESP32-S3, portduino) so every hot node can carry rich data as before the cap existed. `enforceSatelliteCaps()` trims each map to the cap on load (returns whether it trimmed); `evictSatelliteOverCap()` trims before each insert. Eviction is by the owning node's hot `last_heard` (stalest first, demoted/absent nodes rank as `last_heard==0`); self is never trimmed.
+
+### On-boot self-care
+
+`NodeDB::nodeDBSelfCare()` runs once identity is established (the constructor after key (re)gen, and `reloadFromDisk()` — _not_ inside `loadFromDisk`, where `getNodeNum()` is still 0). It confirms self is present (warns if a non-empty DB is missing us — a foreign/over-cap file), pins self to index 0, demotes/trims only **non-self** overflow into the warm tier, then rewrites `nodes.proto` **once** and only if it healed something — and never while encrypted storage is locked (it would persist placeholder defaults). `loadFromDisk` deliberately leaves the loaded store untrimmed for this pass.
 
 ### Sync flow: thin NodeInfo + post-COMPLETE_ID replay (no opt-in)