Refresh limit token cache doesn't re-read Keychain when the previous token is still valid (stale account after switching) #300

Environment

• PokeTokenBar 2.5.4
• macOS 26.6 (25G72), Apple Silicon
• Keychain-only install (no ~/.claude/.credentials.json)
• Claude Code, Team plan, switching between two email accounts on the same Team

Problem

After switching Claude Code accounts via /logout → /login (same Team, two emails), the official
5h/weekly limits in PokeTokenBar keep showing the previous account indefinitely, even after
repeatedly pressing Settings → Refresh limit token cache.

• Popover keeps showing Account: edoardo@memoraiz after switching to hello@memoraiz.
• fiveHour/sevenDay stay frozen for many refresh cycles while the local token counter (feeding
  companion EXP) keeps climbing normally — the two data paths clearly disagree.

Root cause (traced in OAuthLimitsProvider.swift)

UsageStore.refreshLimitTokenFromKeychain() calls limitsProvider.fetch(allowKeychainPrompt: true),
which calls OAuthAccessTokenCache.accessToken(allowKeychainPrompt: true) — with the default
bypassCache: false:

if !bypassCache, let cachedCredential, !cachedCredential.isExpired {
    return cachedCredential.accessToken
}

cachedCredential is only cleared by invalidate(), called only from the 401/403 retry path. A
second, independently-valid Team account's token never gets a 401/403 from api.anthropic.com, so
it's returned from memory forever — Keychain is never queried again after the first successful read,
no matter how many times the refresh button is pressed.

This also makes the log misleading: UsageStore.swift logs "limits refreshed from keychain by user action" unconditionally on success, even when the token actually came from the in-memory cache and
Keychain was never touched. My own log shows exactly this pattern for hours after switching accounts.

Different bug from #227/#228 (fixed the .credentials.json file path) and #232 (fixed picking the
right entry among multiple Keychain items) — this install has no credentials file, and presumably
one relevant Keychain item, so neither prior fix applies here.

Steps to reproduce

1. Keychain-only install. Sign into Claude Code as Account A (Team). Press Refresh limit token
   cache once so the popover shows Account A.
2. /logout, then /login as Account B (different email, same Team, so Account A's token stays
   valid server-side).
3. Press Refresh limit token cache again (any number of times).

Expected: limits and account label switch to Account B.
Actual: limits and account label stay on Account A indefinitely.

Suggested fix

Have the explicit user-action path force bypassCache: true — it's already an intentional user
action, same category as the existing 401/403-triggered bypass retry, so there's no
privacy/prompt-avoidance reason to prefer the cache here.