fix(auth): clear before waiting on the network, not after (#2144)

Copilot review round 13. Three of its four findings were one root cause, and
it is a design flaw in the premise this PR started from.

Revoking *before* the clear meant the clear waited up to five seconds on the
network — and anything that wrote OAuth state in that window was then deleted
by a clear reasoning about the grant it replaced. A same-server reauthorization
in the TUI (whose Disconnect/Connect accelerators stay live), a stored-only web
clear for a server that becomes active mid-flight, and another CLI/TUI process
writing to the shared file-backed store all hit it.

`revokeStoredOAuthTokens` is therefore split into `planOAuthRevocation` and
`executeOAuthRevocation`, and every caller runs plan → `storage.clear()` →
execute. The snapshot still precedes the clear, because the store is where the
token, the credentials and the endpoint live; but the clear no longer waits on
anything. There is deliberately no single-call wrapper left, so no caller can
reintroduce the racy order by accident.

Fourth finding, same file: `handleConnect` now retires `clearOAuthAttemptRef`
alongside `disconnectAttemptRef`. The server-name check does not cover
disconnect/reconnect to the SAME server — the name still matches on the other
side of it — so a clear still in flight could tear down the session the connect
had just established.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0177mPHAdECD18nLLCTwR5rh
Signed-off-by: cliffhall <cliff@futurescale.com>

clients/tui/src/App.tsx

@@ -796,6 +796,11 @@ function App({
     // A connect attempt supersedes whatever the last disconnect reported —
     // including one still in flight, which is what the counter bump retires.
     disconnectAttemptRef.current++;
+    // And whatever a pending clear was going to do (#2144). The server-name
+    // check alone does not cover disconnect/reconnect to the SAME server: the
+    // name still matches on the other side of it, so a clear still in flight
+    // would tear down the session this connect just established.
+    clearOAuthAttemptRef.current++;
     setDisconnectError(null);
 
     const finishConnect = async () => {