fix(web): harden managed config sync between console and clients (#2567)

* fix(web): fence managed config runtime reconciliation

Keep runtime reconciliation tied to the currently authorized session so
stale connections cannot mutate a replacement session runtime.

Accumulate only contiguous dirty IDs and load their latest SQLite state.
Require the applied revision to match the earliest Patch base and the
persisted revision to match the latest target. Otherwise, reconcile the
full desired state.

Use separate runtime-state and config-cache epochs. Managed updates can
reuse observed configs; direct mutations invalidate them. Update sync
documentation to match.

* fix(web): interrupt validation retry on state changes

Track meaningful validation state changes separately from periodic dirty signals. Applied revision changes wake a failed validation immediately, while heartbeat-driven revalidation retains the retry backoff.

Treat Notify as a wake-up hint and recheck the state-change epoch after every wake so stored permits and periodic heartbeats cannot cause retry storms.

* fix(web): retry unconfirmed connected webhooks

Retry node-connected webhook delivery on retryable errors with a
short 100ms/500ms backoff and give up immediately on non-retryable
errors. Re-check that the session still owns the connection before
every attempt and before recording the delivery, so a replaced
session can no longer record a stale connected binding.

* fix(web): fence disconnects by session ownership

Return whether session removal actually removed the current route owner, and emit disconnected only for that owner. Replaced sessions can no longer invalidate a newer connected route.

* fix(web): hot-patch managed hostnames

Include hostname changes in the hot-patch path instead of falling
back to a full restart. When a full overwrite run is required and
the desired config has no hostname, inherit the current runtime
hostname so an unmanaged value survives until it is explicitly
cleared.

Read back the runtime config after an overwrite run and verify it
converged instead of assuming the desired state was applied.

* fix(web): retry transient runtime reconciliation failures

Keep the per-session managed runtime reconciliation worker alive when a
single database round fails. Retry from the next heartbeat so persisted
managed revisions can still converge after restart-time contention.

Reserve terminal worker shutdown for destroyed session or storage state,
and cover recovery after a transient revision read failure.

* fix(web): accept omitted hostname after runtime apply

Release 2.6.4 omits hostname from config readback when it matches the device hostname. Trust a successful hostname mutation only when the returned field is absent, while continuing to verify every other field and rejecting explicit mismatches.

* fix(web): ignore unmanaged runtime device names

Windows release 2.6.4 generates a random interface name when the managed config leaves dev_name empty. Exclude that runtime-owned value from reconciliation unless the desired config explicitly sets a non-empty device name, preventing endless overwrite restarts.

* feat(web): report failed network instances to console

Expose stopped Core instances with startup errors in heartbeats.

Merge Core failures with direct managed-run RPC failures in easytier-web.

Send failed instance IDs during token validation without error text.

Prune local run failures when managed configs are deleted.

* fix(web): distinguish unknown runtime application state

Track whether the current session has observed its applied revision
separately from the optional revision value. Report this fact through
validate-token so Console can preserve application state across
receiver restarts while recognizing deliberate pending mutations.

* feat(web): configure heartbeat timing from server

Heartbeat responses now provide the interval and RPC timeout.

Legacy servers use local defaults and remote values are clamped.

Web configuration and session receive timeout follow the policy.

* fix(web): reject inactive control sessions

Route control RPCs by machine id only to sessions whose RPC manager
is still running, so a session that has been stopped or replaced
can no longer receive control traffic addressed to the device.

* fix(core): filter network info before collection

When a collect-network-info request names specific instances,
collect those instances only instead of collecting every instance
and filtering the result afterwards, so unrequested instances no
longer run per-collection work on every request.

* feat(web): enable focused runtime diagnostics

Enable easytier-web info logs by default while preserving explicit log configuration. Record startup settings, session lifecycle, failed instance changes, webhook queue and request latency, and managed runtime operation timings for production diagnosis.

* fix(web): preserve managed revision across reconnects

Keep one runtime identifier for each Core WebClient lifetime.

Reuse its managed runtime state after transport reconnects.

Retain applied revisions and reconcile hints while disconnected.

Preserve runtime epochs so stale work cannot mark a revision applied.

Reject stale sessions from reclaiming routes after reconnect.

Core or Web restarts and legacy clients still use unknown state.

Immediately revalidate a restored revision after authentication.

Document local management RPC drift as an accepted trade-off.

This lets Console converge without waiting for periodic validation.

* fix(web): satisfy clippy across managed config sync tests

Scope managed runtime guards to blocks in runtime revision tests so
no std MutexGuard is held across await points, return the applied
revision directly instead of through a let binding, and pass
WebhookValidationInput to request_heartbeat_validation instead of
expanding it into eight separate arguments.

* fix(core): stop reporting failed instances as running in heartbeats

A stopped instance with a startup error appeared in both
running_network_instances and failed_network_instances, so the
server treated it as running and never re-ran its managed config.
Exclude failed instance ids when building the running list so the
reconciler restarts them.

* fix(core): close missed-wakeup race in instance state changes

wait_for_change created the Notified future before reading the
generation but only registered it when awaited. A change landing in
between fired notify_waiters with no registered waiter and delayed
the heartbeat by a full interval. Enable the future before reading
the generation so every change wakes a waiting heartbeat.

* fix(web): address review findings

Fence webhook validation and connection transitions against stale
state, redact credentials from default-level logs, and stabilize
runtime reconciliation:

- Record connected bindings only while the session still owns the
  machine route, and skip disconnect compensation once a replacement
  owns the route so a stale disconnect cannot revoke it.
- Discard webhook validation results when the change epoch moved
  during the HTTP round, so a stale rejection cannot invalidate the
  current session.
- Drop user_token fields from info and warn logs that became
  visible with info-level defaults.
- Restore a hostname omitted by the 2.6.4 readback into the cached
  runtime config after a successful mutation, so later rounds stop
  re-sending the same hostname patch.
- Reconcile running web configs when no revision is tracked so
  legacy unrevisioned updates converge, and wake sessions for
  unrevisioned full updates instead of waiting for the next
  heartbeat.

* chore(go): regenerate web proto bindings for heartbeat fields

Add failed_network_instances, support_heartbeat_policy, and the
heartbeat policy response fields to the checked-in Go bindings.
Other proto packages are left as-is because their drift predates
this change.

* fix(web): redact user tokens from positional log arguments

Three runtime reconciliation info logs and the user lookup error
contexts printed user_token through format arguments, which the
earlier field-syntax redaction missed. The reconcile log now fires
every round for unrevisioned machines, so remove the token from
these messages as well.

* fix(web): fence stale validation and runtime reconcile rounds

Check webhook validation epochs while holding the session write lock,
so stale success and rejection responses cannot change session state.
Advance the runtime epoch for unrevisioned full config updates, and
exclude failed instances from heartbeat and RPC reconciliation lists
so stopped instances are restarted instead of repeatedly hot-patched.

Release test read guards before awaiting validation apply calls. Set
up the no-pending condition before asserting that an applied revision
is a no-op, and verify that its runtime epoch remains unchanged.

Validation: all 137 client_manager tests passed.

* test(credentials): cover P2P with active VPN portal

Model an admin and temporary credential peer connected as a foreign network through a public server with data relay disabled. Verify their direct connection can be replaced after a WireGuard portal client comes online.

* test(credentials): stabilize two-admins failover assertions

The two-admins non-reusable credential test could fail on slow
convergence: after dropping the winning peer it relied on a single
route sample passing a bare AND condition, then re-asserted the same
expectations through one-shot checks seconds later. A transient route
flap in that window (for example a briefly resurrected winner route
from stale conn info) turned a passing convergence into a hard assert
failure. This matches the 48.9s CI flake of
credential_non_reusable_across_two_admins_allows_only_one_peer
observed on 2026-08-12.

Changes:

- wait for bidirectional admin connectivity (AND) with a 20s budget
  before issuing the credential, instead of a one-directional OR
- replace the failover wait_for_condition with
  wait_stable_failover_visibility_on_admins, which requires three
  consecutive samples of loser-present and winner-absent on both
  admins within the same 60s budget and logs every sample
- enrich the stable-single-winner timeout message with per-admin
  visibility flags and elapsed time for triage

All existing contracts are preserved; only observation windows and
diagnostics change. Validated in the rust container: three passes at
normal speed (54.1s / 53.8s / 53.1s) plus one slow-convergence round
(172.7s) that would have raced the old one-shot sampling; it now
passes with failover samples logged. cargo fmt and clippy -D warnings
clean.