feat(opcuaclient): #676 follow-ups — endpoint rewrite, stall wire test, fast definitive-loss recovery

- 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.

CLAUDE.md

@@ -321,6 +321,12 @@ non-`Healthy` state **and** its `LastSuccessfulRead` has been frozen for 90 s. T
   `DefaultReconnectInterval`. Unlike the #523 drift detector this generates **no** traffic on a healthy
   system — it is a local `GetHealth()` read, and only reaches the network once a driver has already stopped
   reading.
+- **Fast path for DEFINITIVE losses (#676):** a driver implementing the opt-in `IDriverConnectionLossSource` raises
+  `ConnectionLost` (once per connection) when its protocol proves the connection can never recover in place — OpcUaClient:
+  keep-alive `BadSessionIdInvalid`/`BadSessionClosed`/`BadSessionNotActivated`/`BadServerHalted` or a dropped
+  subscription — and `DriverInstanceActor` (attach PreStart, detach PostStop) turns it into the same disconnect only
+  while Connected; ambiguous failures (timeouts, `BadNoCommunication`, a stalled socket) must never raise and stay with
+  the watchdog's conjunction. `docs/DriverLifecycle.md`.
 
 - **What comms loss now does downstream — one contract, six seams (archreview R3-02).** "A value consumer
   never reports a quality better than its source's" is stated once in `docs/DriverLifecycle.md` §"The