Three defects found reviewing the preceding commits.
1. reconnectSlotClient() stranded a STOPPED client, reintroducing the very bug
this branch fixes. It only rebuilt when isStarted() was true and otherwise
fell through to reconnect(), which is a documented no-op on a stopped client
— so nothing restarted it, at any rung, including the breaker probe. The
WiFi-transition teardown reaches exactly this state: it calls the hard
disconnect(), clearing _started while initial_connect_done stays set, so
after WiFi returned the slot could never come back. Now a stopped client is
started with connect() before the rebuild/reuse decision is considered.
The post-NTP credential refresh had the same exposure — it called
reconnect() directly — so it now goes through the helper too, still reusing
the transport since its fault is stale credentials, not the transport.
2. Allocating the neighbors buffer on first use let a stopped bridge allocate.
A neighbour discovery started before a stop can complete after it, and
neither caller rechecks bridge state, so requestPublishNeighbors() would
allocate 4 KB after releaseRuntimeBuffers() had already run and strand
_neighbors_publish_pending with no task to consume it. end() then returns
early on !_initialized, retaining the buffer until a later begin/end or a
reboot. Guarded on isRunning(), the same flag end() checks.
The release/acquire handoff itself was confirmed sound: the allocation and
copy precede the release store, and the task loop reads the pointer only
after its acquire load, so a half-published pointer is not observable.
3. The post-link map check failed open, contradicting the fail-closed claim in
its own commit message. A missing map, an unrecognised map format, or a
partial archive list each warned and passed; and it hardcoded firmware.map
while the post-action target used ${PROGNAME}, so a renamed program could
inspect a stale or absent file and still succeed. All four now fail the
build, and it requires every one of the four archives to appear rather than
at least one.
Rebuilt Heltec_v3_repeater_observer_mqtt, Heltec_v3_repeater and
heltec_v4_repeater_observer_mqtt; the opt-in path still reports all 4 archives
linked from .mbedtls-4k/.
(cherry picked from commit 5b5f076e5e165997e8050f2be061c7c67340fcf7)
allocateRuntimeBuffers() took NEIGHBORS_JSON_BUFFER_SIZE unconditionally on
every board built WITH_MQTT_NEIGHBORS, whether or not mqtt.neighbors was ever
turned on. On a non-PSRAM board that is 4 KB of internal DRAM held for the
bridge's lifetime by a node that may never publish a neighbours snapshot.
Gating the existing allocation on the pref would not work: mqtt.neighbors is
read live by the mesh loop with no bridge restart, so enabling it at runtime
would find no buffer and silently publish nothing. Allocate on first use
instead, in requestPublishNeighbors(), which is reached only when something
actually wants to publish — periodic or a manual discovery.
Publishing the pointer across cores is safe with the existing handshake: the
allocation precedes the release store on _neighbors_publish_pending, and the
task loop reads the pointer only after its matching acquire load, so the
pointer cannot be observed half-published. A failed allocation drops that one
snapshot and retries on the next, rather than disabling neighbours for the
bridge's lifetime as the eager path did.
(cherry picked from commit e6da052a93f8765824d0fb4bd0c704ca3ed3d294)
The scheduled JWT bounce called PsychicMqttClient::disconnect(), which ends
with esp_mqtt_client_stop(). That ends the client task and returns its 6 KiB
stack to the heap at the moment the TLS teardown vacates two 16 KiB mbedTLS
record buffers, so the stack lands in that hole and the next handshake cannot
reuse it. On non-PSRAM boards the largest free block then ratchets down 16 KiB
at a time while total free heap stays flat.
Soak evidence from a Heltec V3 on 8d1a0eb3: 43 of 60 disconnects had no
preceding transport error, i.e. they were this proactive bounce rather than a
broker FIN, and two of the three max_alloc steps landed within 5 s of one.
Losing a whole TLS session later returned exactly 16,384 bytes of contiguity.
softDisconnect() closes the transport without the stop, so the task and its
stack stay put across the handshake. The bounce uses it plus reconnect(), and
falls back to connect() when the client really is stopped, since reconnect()
is a silent no-op in that state.
Also corrects a comment claiming the mbedTLS context survives a transport
close: only the esp-mqtt client object does.
(cherry picked from commit 10cf5cf48fb009e751e25b37fcc1f3d1256ddbbc)
Picks up upstream MeshCore 1.17.1.
Notable upstream content:
- 1.17.1 version/build-date bump in the example MyMesh headers.
- nRF52: combine radio entropy with CC310 RNG.
- Companion FEM prefs: load/save of fem_ properties commented out until they
can be set from the client.
- Scoped reply routing: replies no longer dropped when flood.max.unscoped is
low (RoutingPolicy + unit tests).
- nRF52 unused-pin sweep (T1, T-Echo Lite, MeshPocket).
No conflicts.
Brings in the external FEM gain preferences (fem_txgain, PR #3137 plus the
companion-side port), the AGC reset rxgain fix, the LR2021 preamble/IRQ
timeout logic, and assorted variant fixes (T096, T-Echo Card TCXO, promicro
pinmap, minewsemi, R1 Neo).
Conflict resolutions:
- SH1106Display: both sides fixed T-Beam Supreme startup independently. Kept
our _initialized guard and DISPLAY_ADDRESS_ALT override, took upstream's
SA0-pair fallback and its unconditional display.begin() so the frame buffer
is allocated even when no panel answers.
- MyMesh/SensorMesh/CommonCLI: took upstream's fem_txgain default and wiring,
kept our comments and the observer-side prefs layout.
Also fixes CustomLLCC68Wrapper, which upstream missed when sx126xResetAGC
gained its rx_boost_gain parameter. No variant builds that wrapper today, so
neither tree failed to compile.
Introduced consistent preferences for external LoRa FEM RX and TX gain settings in NodePrefs. Updated companion MyMesh to apply these settings during initialization and transmission. Added unit tests to verify the round-trip serialization of these new preferences.
Nine commits reducing the MQTT bridge's internal-DRAM footprint, plus four
fixes that rode with them (invalid path encodings, stale-JWT scan after a
clock correction, setup-retry interval measured from the failure, retried
setup consuming the reconnect allowance).
Touches no prefs surface -- nothing in NodePrefs, MQTTPrefs, or
ConfigSerializer -- so /prefs.json layout is unaffected and there is no
fleet config risk.
Soak evidence: every soak branch already contained this work in full. Device 1
has run it 69.6 h with 325,852 publishes, 0 errors and 0 reboots. The caveat
worth carrying: that long-duration evidence is all on the reduced-TLS
framework (OUT_CONTENT_LEN 4096). Device 3 is now soaking it on the stock
framework, which is where the allocation-ordering interaction with the full
16 KiB record buffers actually gets exercised.
Picks up upstream MeshCore 1.17.0 and the dev commits that followed it.
Notable upstream content:
- 1.17.0 version/build-date bump in the example MyMesh headers.
- anon_req hardening: reply_path_len is now uint8_t with an isValidPathLen()
bounds check and a 0xFF sentinel; reply_path_hash_size is gone.
- LR2021 support (Meshnology W12, Seeed MeshTracker X1) incl. side detectors,
multi-SF and the new `extra.sf` get/set CLI.
- CustomLFS 0.2.2 -> 0.2.3 (GD25Q64C support).
- kiss_modem envs for several nRF52 variants; ThinkNode M6 GPS/flash fixes.
Conflicts resolved:
- platformio.ini: took upstream's CustomLFS 0.2.3, kept our lib_ignore for
the vendored PsychicMqttClient.
- CommonCLI.h: kept both upstream's USE_LR2021 configSideDetectors() hook and
our fault-alert callbacks.
NodePrefs gains upstream's extra_sf[4], which is not registered with
ConfigSerializer, so /prefs.json layout is unchanged.
Verified: 275/275 native host tests pass; Heltec_v3_repeater_observer_mqtt,
Heltec_v3_repeater and heltec_v4_repeater_observer_mqtt all build.
LilyGo_TLora_V2_1_1_6 observer builds failed to link:
undefined reference to `WebConfigServer::MAX_BATCH'
in handleStatus and handleCliPost
An in-class initialiser is only a declaration under C++11, which is what the
xtensa-esp32 toolchain builds with. Every previous use of MAX_BATCH was a
comparison, which reads the value and needs no symbol. Reporting it as
status.max_cmds, and naming it in the "too many commands" error, passes it to
ArduinoJson — which takes `const T&` — and binding a reference odr-uses it.
It linked on most targets because the compiler folded the reference away, and
failed on the ones where it did not. A cast at the two call sites would have
silenced it just as narrowly; defining the symbols is what stops the next use
from depending on the same luck. MAX_BODY and STOP_WARN_MS get the same
treatment for the same reason, before they are the next to be passed by
reference.
Two findings from review, both real, both mine.
The CLI could read secrets the portal has never exposed. CommonCLI splits its
surface by CALLER, not by command: a serial caller (sender_timestamp 0, physical
access) reads secrets in plaintext, a remote one gets "******** (serial only)".
Its own comments say so — "Serial only (WiFi creds grant LAN access); remote
sees set/unset". execCommand passes 0, which is what makes `erase`, `stats-*`
and `set freq` reachable at all, and with it the terminal inherited the serial
console's plaintext answers for an HTTP request: `get prv.key` returned this
node's identity, `get wifi.pwd` the operator's network.
Worse in setup mode, which authenticates by proximity to an open AP — and `start
webconfig ap` can be run on an already-configured node, so the secrets are real
by then, not blank.
I had reasoned that the AP was the trust boundary either way because the wizard
can already rewrite these. That conflated two capabilities: replacing a WiFi
password does not reveal the current one, and replacing an identity does not
reveal the existing private key. /api/config has always masked these on read
(wcIsSecretKey); the CLI simply broke that rule. Now only the READ is masked —
the command surface stays whole — in CommonCLI's own words, keeping the
set/unset signal that is the useful part.
Onboarding could also skip the mandatory password. handleConfigPost refuses to
arm a reboot during initial setup without one; the CLI only warned in the
browser, which a pasted script or a direct POST ignores, so a node could reboot
onto the LAN still holding the factory credential. Same rule now applies at
POST. It is satisfied by a `password` command anywhere in the session rather
than only in the same request, so the natural two-step console flow still works
— the form batch always sends both together and never needed that memory.
wcIsSecretReadCommand lives in WebConfigKeys.h beside the rest of the secret
classification, pinned by three host tests: what must be masked, what must not,
and that only reads are touched. 17 keys + 24 batch tests pass; the audit checks
a masked read round-trips as masked.
The full embedded string is v1.16.0.5-observer-beta-dev-a1b2c3d. The -observer
tag is on every observer build and the commit is for machines, so neither tells
a person anything at a glance. Both the page header and the console banner now
show base + published build number + channel, paired with the build date the
way `ver` pairs them:
v1.16.0.5-dev (6 Jun 2026)
v1.16.0.5 (6 Jun 2026)
`ver` still prints the whole string, commit included, for when that is what you
need. The channel suffix follows the release filenames rather than the embedded
tag — build.sh writes FILENAME_CHANNEL_TAG "-dev" for the same builds it tags
"-observer-beta-dev" internally, so "-dev" is the name these already carry.
Carrying the build date meant /api/status had to report it; WebConfigServer now
takes FIRMWARE_BUILD_DATE alongside FIRMWARE_VERSION, from the same defines
`ver` reads.
A local build has neither build number nor channel to show, so the fact worth
knowing about it moves to the second line: "local build, OTA not configured".
build.sh deliberately leaves OTA_MANIFEST_BASE undefined there, and a bare
version number gives no hint that the node cannot update itself.
Five findings from review, all confirmed against the source.
Failure classification (P2). Testing replies for an "Err" prefix passed five
other shapes off as success: "Unknown command", "unknown config: x", "??: x",
"Can't find GPS", "(ERR: clock cannot go backwards)" and "File system erase:
Err". They rendered green, and worse, left _batch_all_ok true — so a queued
reboot went ahead after commands that had failed, defeating the gate entirely.
Rather than lengthen one guess, the two questions are now asked separately,
each erring safe:
- colour asks "does this look like a failure", against every shape CommonCLI
actually emits, enumerated in WebConfigBatch.h and pinned by a host test
that uses the literal strings. Getting this wrong is cosmetic.
- the reboot gate asks something narrower and answerable: "did every setting
I asked for take". Only `set`/`password` gate it, and only on the "OK"
prefix every setter keeps. Diagnostics no longer gate a reboot at all, so a
harmless `memory` cannot strand one and no guess is made about "> value".
Reboot deferral (P2). CommonCLI dispatches on a six-byte prefix, so `reboot
now` and `rebooted` reach Board::reboot() too. Matching exactly meant those
variants skipped both the confirmation and the deferral and took the node down
mid-drain — the precise failure deferral exists to prevent. Both sides now
anchor the way the firmware dispatches, and the UI's risk matcher with them.
Three commands the portal cannot honestly serve are refused at POST with a
reason, and dropped from autocomplete, instead of running and lying:
- `start ota` builds a second AsyncWebServer on port 80 with no bind check
and answers "Started" regardless; the portal already holds that port, so it
could only leak the allocation and inhibit sleep.
- `clock sync` takes its time from the caller's timestamp, which a web
request has none of, so CommonCLI always rejected it. `time <epoch>` works
and remains offered.
- bare `log` and `get acl` write their real output to Serial and hand back a
stub the terminal showed as success; `log` also streams a whole file from
the loop task, stalling the mesh and radio while it does.
The mock now emits the same failure shapes it used to fake as successes, so
these are reproducible off-hardware. 24 batch + 14 keys tests pass; audit
reports 119/119 answered, 0 missing, 4/4 refused with a reason.
Two things hardware turned up.
The whole terminal came back red. The endpoint decided a command had succeeded
by testing its reply for an "OK" prefix — the convention the config batch relies
on, and a safe one there because every allowlisted setter uses it. The CLI
reaches the whole surface, where success has no single shape: setters answer
"OK...", getters answer "> value", `erase` answers "File system erase: OK". Only
failure is uniform ("Err", "ERR:", "Error:"), so that is what the CLI now tests
for.
Colour was the visible half. The other half was worse: _batch_all_ok went false
the moment a sequence contained a `get`, so a script ending in `reboot` was told
some commands had failed and the reboot was withheld.
Replies are green now and red means the node said no, which is what red should
have meant all along. The "> " a getter prefixes its value with is dropped for
display — on the serial console it sets the value apart, here it collides with
the prompt glyph that means "you typed this". The mock emits that marker too;
had it done so from the start, this would have shown up before the flash.
Second: discover.neighbors and discover.scopes did not autocomplete, because
MyMesh::handleCommand intercepts a few commands before delegating to CommonCLI
and the table was built by reading CommonCLI alone. setperm, `get acl` and
`shutdown` were missing for the same reason.
The audit could not have caught that: it drove every command the table offered
and checked the mock answered, which only finds gaps in one direction. It now
also reads the command literals the firmware dispatches on — across CommonCLI,
CommonCLI_Observer and MyMesh — and fails on any the table does not offer. That
check found `shutdown` immediately.
122 commands, all answered, none missing. 22 batch + 14 keys tests pass.
The terminal has been driving the mock since it was built. This is the firmware
side, so it works on hardware.
Same 202 + reqid + poll contract as a config save, for the same reason:
CommonCLI touches prefs, the radio and the filesystem, none of which may be
reached from the async_tcp task. Commands go into the deferred slot and tick()
drains them on the loop task. Unlike a save this is not allowlisted — reaching
what the serial console reaches is the point, and execCommand() already passes
sender_timestamp 0, so the terminal gets exactly the serial console's
privilege. Authentication is the boundary, as it is there.
The CLI shares the config batch's slot rather than owning a second MAX_BATCH
array: both drain on the loop task, both are single-slot, and a duplicate would
cost ~8 KB of permanently resident RAM. Sharing also makes a save and a CLI run
mutually exclusive, which they must be. Each reader checks the kind, so neither
can serve the other's results.
Three things the mock could not have taught us:
- Board::reboot() does not return, so a drained `reboot` would take the node
down before the client read a single result. It is answered rather than
executed, and the batch arms the existing deferred-reboot path once the
results have been read — withheld if any command failed, exactly as a save
withholds one. clkreboot/poweroff/ota update do real work on the way down
and cannot be faked, so they still drop the connection; the UI warns first.
- `password <new>` echoes the new password in its reply. The config path
already scrubbed that by key; a CLI entry has no key, so it is matched on
the command. CLI commands are also kept out of the serial log entirely —
the browser session and the serial console are different audiences.
- MAX_BATCH is 24, not the 64 the page assumed. It is reported as
status.max_cmds instead of hardcoded, so the cap cannot drift.
Results stream and page (kCliResultPage = 8), and "done" means the client has
been handed every result, not merely that execution finished — otherwise a
client that stops polling at "done" loses the last page. Commands are never
echoed back: they may carry a secret, and the client matches by index.
New decisions live in WebConfigBatch.h with the rest, covered by three host
tests. Builds clean for heltec_v4_repeater_observer_mqtt; 22 batch + 14 keys
tests pass; the CLI audit reports 119/119 against the updated mock.
canSerialize() validated payload_len and the destination size but not whether the
path encoding is one writePath() will actually emit. writePath() self-guards
against overrunning the path array, but it does so by writing nothing and
returning 0 — a correctness problem, not a safety one, because getRawLength()
still counts the path. An over-long or reserved encoding therefore passed the
size check and then serialized to a truncated frame that was published as the
packet.
Worst case is path_len 0xFF with no payload: 63 hops of 4 bytes counts as 254
bytes, inside the 255-byte buffer, while writeTo() emits just the 2-byte header.
The `raw` field would carry 4 hex chars presented as the frame. Reserved 4-byte
hash encodings passed too, producing frames Packet::readFrom() rejects.
Now gated on Packet::isValidPathLen(), which rejects the reserved 4-byte hash
size and any count * size above MAX_PATH_SIZE in one predicate. It is the same
check readFrom() applies to every received packet, and TX packets are built via
setPathHashSizeAndCount() with real hash sizes, so no decodable packet is turned
away.
Two tests added for the cases a destination-size check cannot reach. The existing
truncation test passed for the wrong reason -- its payload_len of 4 pushed
getRawLength() to 258 and tripped the size check, masking the hole -- so it is
split into the >0xFF truncation case and the counted-length-fits case, with the
254/2-byte asymmetry asserted explicitly so it cannot be masked again.
274/274 native tests; both observer envs and an nRF52 repeater build clean.
The post-NTP-correction refresh looped to _max_active_slots, which is a count of
activation positions and never an index bound. The indices holding those
positions are not contiguous: a slot passed over by isSlotReady() -- or, since
the demand-driven work, by a failed setup -- leaves a higher index activated. On
a two-position board that meant slots 1 and 2 could be live while only indices 0
and 1 were scanned, so slot 3 kept a JWT issued against the pre-correction clock
until its own expiry or a reconnect regenerated it.
Now bounded by RUNTIME_MQTT_SLOTS. The existing guard already skips disabled,
non-JWT, and clientless slots, so widening the range cannot touch a slot that
was never set up.
Pre-existing (the loop predates the demand-driven work) and kept as its own
commit so it can be picked separately. Audited the other _max_active_slots uses:
all are count comparisons or log arguments, so this was the only misuse.
last_reconnect_attempt starts at zero and teardownSlot() re-zeroes it, so the
retry gate in maintainSlotConnections() reduced to "uptime >=
SLOT_SETUP_RETRY_INTERVAL". Past 60 s of uptime a failed setup was therefore
retried on the next maintenance pass rather than 60 s later -- in the same task
iteration for a live reconfigure, since reconfigure processing runs before
maintenance in the loop.
setupSlot() now stamps last_reconnect_attempt on each failure that represents a
real attempt (client allocation, and both JWT token paths), so all three callers
get the interval measured from the failure. The bounds check and the !enabled
early return are not attempts and stay unstamped. The reconnect ladder reads
this field only for slots with initial_connect_done set, which a failed setup
never sets, so reconnect timing is unaffected.
The retry path's own pre-call stamp is kept as a backstop for any future
false-returning path that does not stamp itself.
reconnect_attempted_this_cycle is computed once before the maintenance loop and
only maintainSlotConnection() was setting it. The deferred-setup retry armed the
15 s cross-slot guard via _last_slot_reconnect_ms but left the local flag false,
so a disconnected slot later in the same pass still saw "no reconnect yet" and
started a second TLS handshake. Two concurrent ~40 KB sessions is exactly the
contention the guard prevents, and it landed in the one situation where internal
heap is already known to be short -- a failed allocation is why the retry runs.
Set on success only: setupSlot() returns true only after client->connect(), so
success means a handshake was launched. A failed retry launches nothing and
continues to spend only setup_retry_this_cycle, which rate-limits the allocation
attempts without consuming the handshake allowance.
[P1] A failed setup no longer strands the slot. setupSlot() returns bool and the
startup loops count only successful activations, so a slot that fails on a client
allocation neither consumes an active-slot position (starving a later healthy
broker on capped hardware) nor sits dead forever: maintainSlotConnections()
previously skipped clientless slots and the reconnect ladder is gated on
initial_connect_done, so nothing retried it. It now retries an enabled but
unactivated slot on a 60 s timer, one per cycle, gated on the same
_slots_setup_done ordering so the NTP-deferred setup sequence is preserved.
[P2] JWT setup no longer proceeds without a usable token. Both the preset and
custom-audience paths returned after ignoring createSlotAuthToken()'s result,
then called connect() and latched initial_connect_done -- so the token-allocation
failure introduced by the previous commit produced an unauthenticated attempt
exactly when memory was exhausted. They now return false and let the retry path
handle it.
[P2] ensureSlotAuthToken() no longer clears an existing token. It cleared
unconditionally, so every renewal wiped the current token before JWTHelper ran;
a renewal that then failed left an empty password where the inline buffer used to
preserve working credentials (JWTHelper writes only on success). Only freshly
allocated buffers are initialised now.
[P2] Raw publications reuse the shared document. buildRawJSON() reached
MQTTPayloadBuilder::buildRawMessage(), which constructed its own default
JsonDocument and therefore malloc'd and freed an internal-heap variant pool per
message -- on the highest-rate topic. The document is threaded through both
builders and the bridge passes _json_scratch_doc.
[P3] The writeTo() guard validates the source fields, not just the destination.
A corrupt payload_len of MAX_PACKET_PAYLOAD + 1 still leaves getRawLength()
inside MAX_TRANS_UNIT, so writeTo() read past packet->payload. Sizing and
validation moved to a pure MQTTWireScratch header with host tests covering the
accept/reject edges, matching the MQTTPacketFilter/MQTTConnectionPolicy pattern.
Two findings fell out: MAX_PATH_SIZE one-byte hops is not encodable (the hop
count is 6 bits, so 64 & 63 == 0; 32 two-byte hops is the widest real path), and
a zero-payload packet serializes but does not survive readFrom() -- pinned as a
test because it constrains any future wire-only queue.
[P3] Corrected the pool-size comment: these targets are 32-bit, so
ARDUINOJSON_SLOT_ID_SIZE is 2 and a pool block is 128 slots / 1024 bytes, not
4096. The 4096 figure came from a pre-existing comment near
NEIGHBORS_DOC_POOL_BUDGET, which is left alone -- its byte measurements are
empirical and still stand, only the block-size attribution is wrong.
Activation is now centralized in activatedSlotCount()/canActivateSlot(), used by
both startup loops, the retry path, and applySlotPreset(). That closes the
pre-existing divergence where a live preset change called setupSlot() without
consulting _max_active_slots, letting a non-PSRAM board reach three concurrent
TLS sessions against a cap of two. BEHAVIOUR CHANGE: a reconfigure that would
exceed the cap now logs and leaves the slot inactive instead of connecting.
Reconfiguring an already-active slot still works, because teardownSlot() releases
its position first.
272/272 native tests pass (5 new); both observer envs and an nRF52 repeater build
clean. Flash 1593249 B non-PSRAM, 1555625 B PSRAM.
ensureSlotAuthToken()/releaseSlotAuthToken() now use the bridge's existing
psram_malloc/psram_free rather than malloc/free, so a JWT slot's 768-byte token
comes out of PSRAM instead of internal DRAM. On PSRAM boards this is the larger
half of the auth_token work: the previous commit reclaims 768 B per slot that
never creates a token, while this reclaims 768 B per slot that does -- up to
3840 B of internal DRAM on a fully configured five-slot board, which is where
the mbedTLS working set is competing for space.
No effect on non-PSRAM boards: psram_malloc falls back to internal DRAM, so the
buffer stays exactly where the previous commit left it. Same for a
BOARD_HAS_PSRAM board whose PSRAM fails to initialise.
Safe to move because every access is a CPU copy on the bridge task, never DMA,
an ISR, or a cache-disabled window: JWTHelper memcpy's the token into this
buffer, and esp-mqtt copies it out of _mqtt_cfg into its own internal-DRAM
storage when connect() applies the config. This is unlike the PSRAM-backed MQTT
task stack that was tried and reverted for resetting Heltec V4 boards, where
the fault was PSRAM execution context rather than a plain buffer read.
Split from the previous commit so it can be reverted alone if hardware soak
shows any PSRAM-related instability on the JWT path.
flash non-PSRAM 1592801 -> 1592865 B (+64)
PSRAM 1555213 -> 1555237 B (+24)
267/267 native tests pass; both observer envs and an nRF52 repeater build clean.