[3/4] Recover preferences on login and CLS reconnection

[Sheng Chen (jdneo)]

Stack

Layer 3 of 4 for nonblocking Eclipse chat preferences (#408). Depends on #453; base is jdneo-preferences-02-safe-background-saves at 139798b0db72bb8fc9b3fe3aa356dfb03545eb02. Bottom layer: #452. Implements only ticket 03 of the approved local specification; bounded shutdown saving remains for layer 4.

Changes

• Emit a lifecycle notification from the actual pinned LSP4E StreamConnectionProvider.handleMessage hook after the outgoing initialized notification. LSP4E reaches this only after successful initialization and creates a fresh provider on restart. Deduplicate per provider and identify each connection incarnation; do not infer reconnection from authentication notifications or poll.
• Let lifecycle-owned preference storage retry failed/unavailable initialization on login/account transitions and connection initialization, using its existing coalesced asynchronous loader, 15-second deadline, and manual retry. Pending loads join; same-account READY/dirty choices and failed save status remain intact.
• Notify account changes even when the authentication status remains OK, with stable account snapshots for queued listeners. Invalidate mode discovery immediately on actual authentication transitions so rapid sign-out/sign-in cannot publish old callbacks. Retry failed mode discovery on recovery without reloading ready preferences.
• Unregister authentication/connection listeners on disposal; retain layer 2's captured save destinations, serialized writer, and accepted-save draining. No protocol, preference format/path, policy, file-protection, or shutdown changes.

Verification

TDD red/green regressions cover login, actual initialized-message-to-controls recovery with SWT responsiveness, failed mode discovery, duplicate notifications, manual/recovery races, stale timed-out responses, account switching during saves, signed-out/disposed signals, and rapid same-account sign-out/sign-in with real AuthStatusManager.

All commands used command-local JAVA_HOME=C:\Users\sheche\.jdks\ms-21.0.11 and -B -Dtycho.disableP2Mirrors=true:

• Focused reactor verify: preference/storage/model/chat-base/referenced-file tests and authentication/stream-provider tests passed.
• mvnw.cmd clean verify: passed; 10,810 tests, 0 failures, 0 errors, 8 skips.
• mvnw.cmd checkstyle:check: passed.
• mvnw.cmd test: passed (Tycho executes the actual test suites during verify).

Eight POSIX-specific tests are skipped on Windows; no Linux execution claim. SWTBot probe suite remains skipped by default; the new SWT lifecycle/control tests execute in the Eclipse JUnit test bundle.

Parallel Standards/Spec reviews against the exact layer 2 baseline found no blocking issues and no missing ticket requirements. Standards noted only an existing documentation/API inconsistency: docs prescribe a nonexistent logError helper; this change follows the actual repository LOGGER convention.