1. A per-ref delivery counter (bumped under the delivery lock by every publish path) is
captured before the trailing read is issued; a ref delivered to since is skipped.
Without source timestamps the read's sample could not be ordered against a notification
that landed mid-read, and publishing it regressed the node. Test injects the
notification inside the mocked read, with and without a read source time (red before).
2. Delivery-lock comment corrected (it serialises across subscriptions, which the SDK
dispatches on separate workers); PublishCommsLoss now publishes under the lock too.
3. CancelSessionWork cancels without disposing, so a keep-alive thread reading the old
token cannot hit ObjectDisposedException.
1. RewriteEndpointUrl keeps the advertised port when the configured URL names none
(Uri.Port -1 would have sent the session to 4840); port-less + IPv6 tests.
2. The trailing re-read repairs any (value, status) difference that is not older than
the last delivered value — Good->Bad/Uncertain included; a read without a source
timestamp counts as newer; an equal source time with different content is published
(repairs the replay guard's by-design equal-timestamp drop).
3. One driver-wide delivery lock makes decide+publish atomic across live notifications,
the recovery read and the trailing read, so an older value can never land after a
newer one (deterministic race test via a seam).
4. Known gap documented: a ConnectionLost raised while the host is not Connected is
swallowed and that session falls back to the watchdog.
5. Only a SERVER-reported subscription loss raises ConnectionLost; the publishing-stall
heuristic stays with the #527 watchdog.
6. Post-recovery timers run on Task.Delay(…, Clock, ct) with a session-work CTS
cancelled on session release and dispose.
7. Replay summary at Information only when something was dropped (Debug otherwise);
a re-arm reports the superseded window's drops and counts afresh.
8. DriverInstanceActor: AttachHostStatusSource doc comment restored; Reconnecting
swallows a stray DisconnectObserved (test).
9. Stall wire test: 120 s session timeout, 3000-cycle subscription lifetime, one further
bad keep-alive tick, 60 s headroom on the post-recovery waits (5/5 green).
- Endpoint rewrite: the driver now connects to the configured host AND port (scheme
match, advertised path kept) instead of the server-advertised URL — fixes NAT/port-map
upstreams and lets an in-test proxy carry the session (SDK SelectEndpoint rule).
- TcpStallProxy + OpcUaClientDriverStallWireTests: the in-place blip (#670) is now
wire-tested on loopback — one Bad, frozen read stamp, same session, identical value
republished Good, a post-recovery change arrives, no source-time regression after
the SDK's late backlog flush.
- Defect found by that test, fixed: a change published right after a stall rode a
Publish response the SDK timed out and never republished, leaving the node Good on
the pre-change value indefinitely. New trailing reconcile read (Timeout +
KeepAliveInterval after recovery) publishes any Good value newer than the last
accepted one, through the replay guard's mark.
- IDriverConnectionLossSource (Core.Abstractions): opt-in definitive-loss signal.
DriverInstanceActor attaches in PreStart / detaches in PostStop and turns a raise
into a disconnect only while Connected. OpcUaClient raises once per session on
keep-alive BadSessionIdInvalid/BadSessionClosed/BadSessionNotActivated/
BadServerHalted (measured: the SDK never re-opens a halted channel) or a dropped
subscription; ambiguous codes stay with the #527 watchdog.
- Replay guard: one Information summary per recovery when the window closes
("dropped N late notifications across M refs"), with a timer so quiet
subscriptions log it too.
- ReconnectPeriod deleted (options, AdminUI form, docs, tests); stored configs that
carry reconnectPeriod still parse in the factory, probe and browser.
- Docs: OpcUaClient.md, DriverLifecycle.md, driver-specs.md, CLAUDE.md.
The F2 live gate failed (10 value regressions over 4 blips): IsLateReplay
disarmed a ref on its first in-order notification, which arrives ~1 s after
recovery, while the SDK's late replay lands 4-6 s later. Equal source times
also passed, so a replay equal to the recovery read got through.
While the window is open each ref now carries a high-water mark (seeded at
arming, raised by the recovery read, advanced by every accepted notification);
a notification at or below it is dropped (equal included — OPC UA moves the
source timestamp on every value/status change). Null source time passes
without moving the mark. Window expiry still disarms entirely, so an upstream
clock step-back is never frozen outside the window. Arm/expiry serialised by a
lock so an expiry racing a re-arm cannot wipe fresh seeds.
The global 'never older than the last Good source time' rule froze a node
whenever an upstream clock stepped backwards (NTP correction, PLC clock
reset) until the clock caught up. The check is now a replay guard armed
only by a same-session recovery (keep-alive bad->good): per ref it holds
the last Good upstream source time (raised by the recovery read), a ref
disarms on its first in-order notification, and the whole guard expires
after max(30 s, 2x the longest subscription keep-alive window). Outside
it every notification is accepted. The steady-state tracker records the
LAST accepted time, not a high-water mark.
F1: the driver's outage BadNoCommunication carried the last Good sample's
source timestamp. The recorder historizes SourceTimestampUtc ??
ServerTimestampUtc, so the Bad landed on the Good row's (TagId,
SourceTimeUtc) key and the insert-if-absent historian dropped it - no
outage marker until the host's watchdog marker ~95 s in, none at all for
a short blip. Now stamped with the detection time (source + server), as
the host's comms-loss fan does.
F2: after a same-session recovery the SDK delivered a missed notification
seconds late with an older source time and the node regressed. A
notification older than the newest Good upstream source time for its ref
(notification or recovery read) is dropped and counted
(stale_notification_dropped); equal timestamps pass; the outage Bad never
moves the comparison; a re-initialise resets it.
M1: a subscription that dies while the session lives (outage longer than
the subscription lifetime but shorter than the session timeout) used to
end Healthy with fresh keep-alive stamps and frozen values. PublishError
BadNoSubscription / BadSubscriptionIdInvalid naming a tracked
subscription, or a tracked subscription whose SDK PublishingStopped
persists one more keep-alive window + 5 s across good keep-alives, now
declares it lost: Degraded, outage published once, and nothing advances
LastSuccessfulRead until the session is released, so the #527 watchdog
re-initialises and re-subscribes. Both detectors wire-tested.
M2: in-place recovery is bound to the session whose keep-alive recovered;
one overtaken by a re-initialise no longer re-arms the new session's
outage latch or degrades its health (ReadCoreAsync expectedSession).
L1 CAS health updates; L2 re-check before each recovery publish; L3 skip
CloseSession on a lost session; L4 SDK log forwarding rate-limited
(20/min); L5 per-driver SDK LoggerFactory disposed with the driver.
Wire test asserts the read stamp stays frozen while the server is down.
A bad keep-alive now degrades health (LastSuccessfulRead preserved) and,
once per outage, publishes BadNoCommunication (value retained) for every
subscribed ref plus a quality-only annotation on subscribed alarm
conditions. Good keep-alives and data/event notifications advance
LastSuccessfulRead, so an idle-but-alive subscription never looks dead
to the #527 watchdog. A keep-alive that recovers on the same session
re-reads the Bad refs and republishes them Good; a session that does not
come back is recovered by the watchdog's ShutdownAsync + InitializeAsync
+ re-subscribe.
Deletes the SessionReconnectHandler wiring (it retried forever in SDK
1.5.378, cloned subscriptions the driver never re-tracked and kept health
Healthy), OnReconnectComplete, TryRearmReconnect and the reconnect_*
counters (new keepalive_recovered). Teardown of a lost session skips
wire deletes and bounds CloseSession. SDK warnings reach the driver log.
Wire test reworked: restart => Bad, then watchdog-style reinit => Good.
- Historian.md: Empty samples always Bad (writer/updater/read clamp),
long-name refusal, 5 s bootstrap failure cache, AtTime after now, info-bit
masking, HistoryUpdate does NOT type-check (M-1 decision), DeleteRaw
needs both bounds, reverse Raw paging, the historian/historization metric
prefixes, and provisioning numeric-only lines qualified as Gateway.
- CLAUDE.md numeric-only lines qualified as Gateway backend.
- Stale 'sole historian' lines in DriverLifecycle, ServiceHosting and the
retired Wonderware stub; Client.CLI exit-code contract.
- ServerHistorianOptions: Endpoint/Backend XML docs untangled, Validate()
indented; Program.cs comments are backend-neutral; T10 week-test day count.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Since #516 a DriverConfig change is stop + respawn, so DriverSpawnPlan.ToApplyDelta
was always empty and the in-place path had no producer. #663 and #664 were both
latent bugs in it. This deletes it:
- host: ApplyChildDelta, _pendingDelta, HandleApplyResult and HandleDeltaApplied
- plan: DriverSpawnPlan.ToApplyDelta
- actor: the ApplyDelta, ApplyResult and DeltaApplied messages, the Connected
reinit handler and the mid-connect AdoptConfigDuringInit
- tests: the actor tests that drove the seam
IDriver.ReinitializeAsync and each driver's implementation and unit tests stay.
Comments and docs that cited AdoptConfigDuringInit as the reason a driver must
release prior state at init now cite the IDriver contract and overlapping
retries, which still apply.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- HardwareGateGuardTests: only StringWriteGateTests may name a write path in HardwareGate/; the
allow-list is exactly the two Z-35162 (10.209.70.160) STRING tags; the opt-in, the (host, tag)
check and the AB_DIFF_ENDPOINT refusal are present. Proven red by a WriteAsync mutation.
- StringWriteGateTests: allow-list entries are (host, tag); any other endpoint is refused; skips
while AB_DIFF_ENDPOINT is set, like IntegrationWriteGate.
- AbCip.md #566: the close happened somewhere in the 16-60 s window; RST vs FIN not captured.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
A. #566 on a real CompactLogix (Z-35162, read-only): a class-3 connection idled 60 s past its
16 s timeout is closed at the TCP level, not with CIP 0x0107/0x0203; the next request fails on
its write (Broken pipe -> BadConnection) in 9 ms and the one after reopens. The transport already
handles this, so no production behaviour changed; the shape is pinned offline by
CipConnectionTests.A_target_that_resets_an_idle_session_... (FakeEipServer.ResetAllConnections),
proven red with a reconnect-skipping mutation. The diagnostics-only exchange tap now also sees
Forward Open replies (granted RPIs).
B. Native STRING write through the driver on Program:ES03_TemperatureControl._StrTmp: write,
read back, restored byte-exact (user-approved). Array write NOT run: the census's unreferenced
DINT[32] _SEQ_EP arrays are aliased sequencer step registers (raw L5X grep), so none qualifies.
#567 still impossible (a 128 B array / 88 B STRING never fragments).
New env-gated harness: AbCip.IntegrationTests/HardwareGate (IdleConnectionEvidenceTests,
StringWriteGateTests). Docs: gate results (hw5 section + raw output), AbCip.md, CLAUDE.md.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
After an OpcUaClient respawn an upstream inactive+unacked condition went out as
Retrigger+Clear (duplicate Activated+Cleared rows, Active flicker), and a
first-sight inactive+acked one as Unspecified (an Activated row for an inactive
alarm; a retained-Active host condition never cleared).
- New AlarmTransitionKind.InactiveUnacknowledged: one projection, rows only for
what changed (Activated+Cleared from acked, Cleared from active+unacked, none
when already inactive+unacked).
- OpcUaClient uses it for moves into inactive+unacked; first sight of an
inactive condition is InactiveUnacknowledged or Clear+Acknowledge, flagged.
- Projector: a flagged Acknowledge on an already-acked condition writes no row.
- E2E tests through DriverHostActor.ForwardNativeAlarm (red-proven).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Review M1: round 1 refused only the rewritten status bits, so S:/O:/I: writes - which
never worked on libplctag because tag creation failed - would have started reaching
the PLC (outputs, status-file words) on the default transport. WriteRefusal now keys
on LibplctagLegacyName.IsTranslated: file number supplied (S/O/I, incl. bit writes
like O:0/3, refused ahead of the parent-word RMW) or status bit rewritten. Reads
unaffected. Docs/comments now true; gate doc notes R bit-number wire evidence is
non-discriminating (L1). 12 new cases fail with the round-1 predicate.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
The read translation R6:0.DN -> R6:0.CON/13 made those names parse in libplctag, which
would have turned a write - previously impossible, tag creation failed - into a masked
write to the control word. LibplctagLegacyTagRuntime.WriteRefusal (via
IAbLegacyTagFactory.WriteRefusal, same plumbing as native) now refuses writes to every
rewritten status bit (R EN/EU/DN/EM/ER/UL/IN/FD, C UA) with BadNotSupported before a
runtime is created; the runtime also refuses as defence in depth. Reads stay
translated. T/C status bits libplctag parses itself keep their pre-existing behaviour.
13 new tests fail with the predicate disabled.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
libplctag 2.6.0 (bundled by libplctag 1.5.2 / NativeImport 1.0.41) pccc.c needs an
explicit file number (parse_pccc_file_num; S is only the status file when a digit
follows) and has no R-file status-bit mnemonics (sub_element_lookup: con/len/pos only;
a /bit is refused on a 6-byte element). So the canonical S:0 (the default probe),
O:0/3, I:0/0 and R6:0.DN failed with BadCommunicationError on a real MicroLogix 1400
while native read them.
LibplctagLegacyName (libplctag adapter only) now emits S2:/O0:/I1: (the native
encoder's implicit file numbers) and R6:0.CON/<bit> for status bits libplctag lacks
(R EN/EU/DN/EM/ER/UL/IN/FD, C UA), bit numbers taken from the native table. The
authored grammar is unchanged. Unit tests pin the translation per family and check,
through a model of the pccc.c parser, that the translated name addresses exactly
what the native encoder does (46 fail without the fix). Live: Z-33323 idle, reads
only - libplctag now equals native for S/O/I/R status bits; controls unchanged.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- L2: WriteWidthRefusal leaves a BOOL over a wider value to a runtime that sees the CIP
type (native): mistyped integer member -> BadTypeMismatch (as its read), 0xD3 BOOL-array
DWORD -> BadNotSupported; libplctag keeps BadNotSupported for both (size only).
- L4: direct theory over WriteWidthRefusal (1/2/4/8 widths incl LINT/ULINT/LREAL, String/Dt,
unknown size) + array/bit-selector exemptions with a non-vacuous control.
- L1: CLAUDE.md member/BIT-member writes are ab_server-proven only.
- L3: patch 0003 blind spots documented (Docker README, AbServer-Test-Fixture.md); nits.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Item 2 — controller-discovered UDT members are writable on both transports once
browse-committed and authored ReadWrite (writability is the operator's: the commit
lands AccessLevel Read with no writable key). The write names the member (one CIP
symbolic segment per member), its own type, its own bytes. BIT members are supported:
Z-35162 (read-only probe) exposes a UDT BIT member as a 1-byte 0xC1 BOOL, so the
controller applies the bit and the hidden host's other bits are never in the request.
- AbCipDriver: pre-write width check on BOTH transports (libplctag patched part of
its read buffer and sent it all): BadTypeMismatch, Bool over a wider value
BadNotSupported; nothing sent, handle kept, health untouched, warn once.
- A runtime NotSupportedException is a refusal: no longer latches Degraded.
Item 3 — whole-UDT writes refused BadNotSupported before any runtime exists, by
decision (a structure write overwrites hidden hosts + padding), documented.
ab_server patch 0003: serve member paths from dotted flat tags (UdtSeg.*), and
accept libplctag's pad byte on 1-byte writes (stock ab_server refused every
libplctag BOOL/SINT write with 0x03). New AbCipUdtMemberWriteTests (both
transports), AbCipDiscoveredMemberWriteTests, native request-byte theory, and a
browse-commit mapper pin. Docs: AbCip.md Member writes / Whole-UDT writes / Known
gaps, fixture docs, CLAUDE.md AB section.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
M1 drop-out is a no-row Unspecified+IsRestatement update (projector case); M2 ack judged over every declared
limit; L1 ActiveAcknowledged for an already-acked new limit; L2 Bad Acked/severity carried/skipped; L3 host
end-to-end test; L4 BOOL member-by-member tests + mixed ALMD/ALMA; L5 detection requires no plain Acked.
ALMD active bit is InAlarm per Rockwell's ALMD reference; InFaulted is input health.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Detect ALMA by declared *InAlarm members; one condition per tag keyed on RawPath; severity/message from
the most severe active limit; Raise/ActiveAcknowledged/Retrigger/Clear/Acknowledge; ack writes OperAckAll.
Unit-tested over fake runtimes only (no ab_server ALMA support, Z35162 has none).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
- ReadBucketAsync: the once-per-device "sum-read chunk failed" Warning fires only after a successful
connect; a connect/backoff failure is the connect path's to report. TwinCATSumChunkWarningTests pins
it (no warning across connect failures, exactly one across two later failing sum polls; red without
the guard) plus a source guard that ReadGroupAsync builds its SumRead only via CreateSumRead.
- Docs: diagnostics live-gated via the driver harness (/hosts not exercised); TC2 costs 8 reads on the
first tick and after each reconnect, then <= 4; read counts attributed to the unit tests.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Read-only live gate on Elma presses Z35474 (TC3 3.1.4024) and Z34834 (TC2 2.11):
- Sum-read: every chunk came back BadCommunicationError. Beckhoff's
SumRead(IList<IgIoSumReadEntity>) ctor casts to IList<SumDataEntity>, which
throws InvalidCastException for a List<> (only an array survives via
covariance). The fake-client tests never built a real SumRead. New
AdsTwinCATClient.CreateSumRead passes an array; TwinCATSumReadConstructionTests
pins it (red on the List form) plus a falsifiability control on the library.
After the fix: 59 tags, status identical everywhere, values identical on every
non-moving tag, ~0.35-0.66 s vs ~2.7 s per poll; TC2 CE 2.11 answers sum reads.
- An unexpected sum chunk failure now logs one Warning per device (it was
invisible: the health message was overwritten by the next good read).
- Diagnostics: TC2 has no TwinCAT_SystemInfoVarList; fall back to .SYSTEMINFO /
.SYSTEMTASKINFOARR[1] once the TC3 name answers not-found (live: all six keys).
- #612 browse: Flat verified on TC3 (10,770 leaves; VirtualTree 1,459 strict
subset) — comment and docs updated, no load-mode option needed.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
The hw2 read-only Makino gate (Z-34184, 31i-B) logged the fixed-tree bootstrap failing with
ObjectDisposedException: FocasWireClient. EnsureConnectedAsync was unserialized: the alarm poll
loop and the fixed-tree loop both reached it right after init, the second saw the first's
still-connecting client as not connected, disposed it and opened a second session, and the first
caller's catch then disposed the second caller's client (and recorded a spurious backoff failure).
A per-device ConnectGate now serializes the connect with a re-check after acquire, and the failure
path disposes only its own client. FocasConcurrentConnectTests goes red without the gate.
Docs: a Byte PMC tag is signed, so G12 at 100% feed override reads -101 on the Makino and the
recipe's 255 - value gave 356; recipe now masks. Adds the live statinfo/alarm-watch observations.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
R1: NativeAlarmProjector treats Raise-on-Active as a re-statement only when the message matches what
the condition shows; a different alarm appearing during a respawn un-acks and writes its alerts row.
FOCAS condition messages are a deterministic function of the matched set (tested across fresh driver
instances and reordered lists); Runtime E2E now covers both the same alarm and a new one during a
respawn. Residual (source message determinism) documented in AlarmTracking.md.
R2: a non-OK cnc_rdalmmsg2 return is thrown as FocasWireException{Rc} and classified as a CNC
refusal: conditions get a quality-only BadNotSupported once, one Warning, polling continues, and
driver health is untouched (no 90 s watchdog reconnect loop on a production control). Only transport
faults degrade (falsification control in the test).
R3: alarm-path health is tracked apart from the value path and combined in GetHealth: worst state,
later LastSuccessfulRead. A good value read can no longer mask a failing alarm read (no per-poll
/hosts flip) and a good alarm read cannot mask a value Degraded.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
MAJOR-1: a deploy that changes a driver's config respawns it, and the fresh instance's empty told
record re-sent Raise for every still-active alarm, un-acking acknowledged conditions and writing a
duplicate "Activated" alerts row. NativeAlarmProjector now treats Raise on an already-active
condition as a re-statement (keeps Acked; ForwardNativeAlarm skips the alerts row); only Retrigger
(or inactive->active) un-acks. Sources whose upstream ack state is authoritative send Retrigger for
an unacked re-statement: OpcUaClient on first sight (no prior told), Galaxy for an unacked active
snapshot entry. Runtime E2E drives a FRESH FOCAS driver after a redeploy and asserts the ack survives.
MAJOR-2: a failed FOCAS alarm read annotates each subscribed condition BadNoCommunication once per
outage (#626 quality-only path) with one Warning (MINOR-6), lifted to Good on recovery; failed alarm
reads degrade driver health with LastSuccessfulRead frozen (successful ones advance it), so an
alarm-only driver trips the #527 comms-loss watchdog.
MINOR-3 CLAUDE.md #630 bullet; MINOR-4 split line; MINOR-5 a non-empty cnc_rdalmmsg2 payload that
fits neither stride throws; MINOR-7 value-tag + parsed-address tables are built and swapped, never
cleared in place under the retained poll engine. Docs corrected (FOCAS.md, AlarmTracking.md, CLAUDE.md).
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
An ALARM: address (*, <Type>, <Type>/<n>, <Type>/<lo>-<hi>, T<code>, OTHER) on a raw tag that
also carries the cross-driver alarm object is ONE condition with ConditionId == RawPath and a
Kind (Raise / Retrigger / Clear), so DriverHostActor.ForwardNativeAlarm routes it and
NativeAlarmProjector activates it. Fixes all seven triage defects:
1. SubscribeAlarmsAsync treated the host's RawPaths as device hosts -> nothing polled.
2. Decorated "{host}#{Type}:{Number}" ConditionId -> every event dropped.
3. No Kind -> projector kept prior state.
4. WireFocasClient.ReadAlarmsAsync answered [] on failure -> mass clear + un-acked re-raise.
It now throws; a failed device read keeps every condition's state.
5. Acks lost on reconnect -> told-record dedup (MTConnect #626 pattern) held for the driver's
lifetime; same-set re-subscribe / re-init re-raise nothing; changed set prunes leavers only.
6. Subscribe threw while AlarmProjection.Enabled=false -> the tag is the opt-in; flag is a no-op.
7. Alarm tags could not be authored -> ALARM: grammar (FocasAlarmSelector, Contracts) backs the
editor, the address picker, the deploy-time inspector and driver init.
Severity: authored alarm.severity -> exact OpcUaSeverity; else the 16i-era type bucket. The type
table stays the only one (moved to Contracts, documented 16i-era; 30i codes not invented; raw
T<code> selector + raw code in every message). Read-only: ack is server-side. Also clears the
value table on a re-initialise (#630 gap that let a removed/moved tag keep reading).
E2E: Runtime.Tests FocasNativeAlarmEndToEndTests drives the real driver through the real
DriverHostActor and asserts the condition goes Active then inactive.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
Strict width+kind eligibility for sum-batched scalars (others read singly); latch only on ADS
1793/1794, split 1792/1797/1798 without latching; 32 KiB per-command budget and 500-item ceiling;
short sum response handled per item. Diagnostics: opt-in diagnosticsEnabled (default off), reuse the
probe's ReadState, sample after the host-state transition, JitterMs renamed HeadroomMs, compact
per-device line so many devices fit the 16-entry cap, unavailable-symbol latch cleared on reconnect.
AdminUI: min/max on sum-read max, diagnostics checkbox. Pure planner extracted and unit-tested.
Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe