diff --git a/docs/superpowers/specs/2026-07-12-upstream-0.42.1-windows-port-design.md b/docs/superpowers/specs/2026-07-12-upstream-0.42.1-windows-port-design.md
new file mode 100644
index 0000000000..3b3bf0710f
--- /dev/null
+++ b/docs/superpowers/specs/2026-07-12-upstream-0.42.1-windows-port-design.md
@@ -0,0 +1,221 @@
+# Upstream 0.42.1 Windows Port Design
+
+## Scope
+
+Current `main` is released as Win-CodexBar 0.42.0. This release ports the
+behavioral changes from `steipete/CodexBar` v0.42.1 into the active Windows
+Tauri shell and shared Rust crate. It does not port the Swift/AppKit/WidgetKit,
+website, or appcast structure; the seven PRs below implement Windows behavior
+only.
+
+Each PR is independently reviewable and uses focused TDD. Do not combine these
+changes into a framework migration or an upstream source sync.
+
+## PR 1: Bound Codex JSONL Metadata and Preserve Unpriced Events
+
+**Likely target paths:** `rust/src/core/jsonl_scanner.rs`,
+`rust/src/codex_costs.rs`, `rust/src/cost_scanner.rs`,
+`rust/src/core/cost_pricing.rs`, and their existing unit tests.
+
+- Bound every session-metadata JSONL line/read to 256 KiB. An oversized or
+  malformed line must not grow an unbounded buffer; consume it safely and
+  promptly release its read chunks after scanning.
+- Treat a token event without an attributable model as explicitly unpriced.
+  It may contribute to token observability, but it must not receive fallback
+  model pricing, contribute dollar cost, or be reported as a priced model.
+- Keep model attribution deterministic across incremental scans and cache
+  reloads. An oversized line must not invent an attribution.
+- Cover the byte cap and chunk release, recovery to a valid later JSONL line,
+  and a model-less token event.
+
+## PR 2: Factory API Credential and Source Semantics
+
+**Likely target paths:** `rust/src/providers/factory/mod.rs`,
+`rust/src/settings/api_keys.rs`, `rust/src/settings.rs`,
+`rust/src/core/credentials.rs`, `rust/src/core/provider.rs`,
+`apps/desktop-tauri/src-tauri/src/commands/provider_settings.rs`,
+`apps/desktop-tauri/src/surfaces/settings/providers/ProviderDetailPane.tsx`,
+and `apps/desktop-tauri/src/surfaces/settings/providers/ApiKeySection.tsx`.
+
+- Store a Factory API key through the existing encrypted credential path; it is
+  never serialized into ordinary settings, diagnostics, UI state, or logs.
+- Add Factory API as a source and make Auto API-first when a key exists. Fall
+  back to web only for a recoverable API failure such as timeout, transient
+  transport failure, or server failure. Invalid credentials, authorization
+  failures, malformed API data, and configured-source errors remain explicit
+  API errors and do not silently become a web request.
+- Surface the selected source in the existing provider source UI and preserve
+  the source setting through reloads.
+- The API key must never be attached to the Factory web endpoint request or
+  included in an error string, trace, diagnostic, or redacted-copy payload.
+- Add focused provider and credential-storage tests, including the no-web-key
+  assertion and the recoverable/non-recoverable fallback split.
+
+## PR 3: Claude Passive Probes and Credential State
+
+**Likely target paths:** `rust/src/providers/claude/mod.rs`,
+`rust/src/providers/claude/oauth/mod.rs`,
+`rust/src/providers/claude/oauth/refresh.rs`,
+`rust/src/providers/claude/cli_reset.rs`, `rust/src/settings.rs`,
+`rust/src/core/provider.rs`, `rust/src/cli/tty_runner.rs`,
+`apps/desktop-tauri/src-tauri/src/commands/providers.rs`,
+`apps/desktop-tauri/src/surfaces/settings/providers/sections/credentials/ClaudeCreds.tsx`,
+and `apps/desktop-tauri/src/surfaces/settings/providers/ProviderDetailPane.tsx`.
+
+- While a passive Claude CLI probe runs, disable Claude Code's background
+  updater for that probe process only. The passive probe still runs during an
+  automatic refresh; explicit and manual probes keep their normal behavior.
+- Detect a logged-out Claude CLI before starting an interactive usage probe and
+  return the existing authentication-required error without launching a probe.
+- Persist the successfully selected source after Claude login, so subsequent
+  refreshes use the working source rather than repeating source discovery.
+- An expired OAuth credential may fall through only for an Auto attempt whose
+  CLI result is MCP-only and has no plan-limit sample. Explicit OAuth keeps its
+  OAuth error, and a normal CLI/auth failure does not acquire an unrelated
+  fallback.
+- Mark synthetic CLI placeholders as non-observations: they do not enter
+  notification, history, or reset state. PR 5 owns the shared state guard and
+  is reviewed alongside this PR.
+
+## PR 4: Provider Compatibility and Local CLI Discovery
+
+**Likely target paths:** `rust/src/providers/amp/mod.rs`,
+`rust/src/providers/kiro/mod.rs`, `rust/src/providers/kiro/version.rs`,
+`rust/src/cli/tty_runner.rs`, `rust/src/providers/codex/mod.rs`,
+`rust/src/providers/gemini/mod.rs`, `rust/src/providers/gemini/api.rs`, and
+their existing tests.
+
+- Parse Amp daily usage percentages directly from the current daily response;
+  do not reinterpret a daily percentage as a monthly quota.
+- For old Kiro CLI versions, attempt the bounded pipe invocation first, then
+  use the existing ConPTY mechanism only when needed. Both attempts share one
+  caller deadline, and timeout, cancellation, and parse failure clean up the
+  spawned process tree before returning.
+- Discover the Codex executable bundled with ChatGPT in addition to the
+  existing PATH/npm locations. Invoke the resolved executable directly rather
+  than routing through a shell.
+- Verify Gemini OAuth recovery with focused existing tests. Change Gemini only
+  if that verification exposes a regression; this PR does not duplicate a
+  recovery path that already works.
+
+## PR 5: Codex Reset and Notification Integrity
+
+**Likely target paths:** `rust/src/notifications.rs`,
+`rust/src/core/usage_snapshot.rs`, `rust/src/core/rate_window.rs`,
+`apps/desktop-tauri/src-tauri/src/state.rs`,
+`apps/desktop-tauri/src-tauri/src/commands/providers.rs`, and their tests.
+
+This PR follows PR 1 and is reviewed alongside PR 3.
+
+- Key Codex reset and notification state by stable account owner, rate-window
+  identity, and reset boundary. Display labels, transient emails, and provider
+  IDs alone are not ownership keys.
+- Accept an observation only when it belongs to the same owner and window and
+  advances to a valid later reset boundary for that cycle. Reject stale,
+  cross-account, regressed-boundary, and synthetic-placeholder samples before
+  they mutate notification suppression, history, or reset state.
+- Preserve legitimate reset transitions: a new owner or genuinely advanced
+  boundary starts a new cycle; a rejected sample cannot clear an alert or
+  overwrite a later reset.
+- Test each accepted and rejected transition at the shared state boundary, not
+  by adding equivalent guards to individual providers.
+
+## PR 6: Deterministic Offline Adaptive-Refresh Replay
+
+**Likely target paths:** `apps/desktop-tauri/src-tauri/src/auto_refresh.rs`,
+`rust/src/cli/mod.rs`, `rust/src/cli/usage.rs`, and the existing shared core
+module tree under `rust/src/core/`. A small new
+`rust/src/core/adaptive_refresh.rs` policy module and
+`rust/src/cli/adaptive_refresh.rs` command module are allowed if the existing
+files cannot hold the pure policy cleanly.
+
+- Extract the production adaptive-refresh decision policy into one pure shared
+  Rust core. The Tauri scheduler supplies clock and live observations; it does
+  not own a separate policy.
+- Add a Rust CLI replay command that accepts caller-supplied JSONL observations
+  and emits deterministic decisions. It is offline: it performs no provider,
+  network, credential, or desktop-shell access.
+- Replay has no production recording path. Tests create their own input data,
+  and production refresh does not write user observations solely to support
+  replay.
+- Use fixed caller-supplied times in replay tests so equal JSONL always
+  produces equal output.
+
+## PR 7: German UI, Settings Grouping, and Cost-History Rendering
+
+**Likely target paths:** `rust/src/settings.rs`, `rust/src/locale.rs`,
+`rust/src/locale/tests.rs`, `rust/src/locale/de-DE.ftl` (new),
+`apps/desktop-tauri/src/i18n/keys.ts`,
+`apps/desktop-tauri/src/i18n/LocaleProvider.tsx`,
+`apps/desktop-tauri/src/surfaces/settings/tabs/GeneralTab.tsx`,
+`apps/desktop-tauri/src/surfaces/settings/providers/ProviderDetailPane.tsx`,
+`apps/desktop-tauri/src/surfaces/settings/providers/sections/MenuBarMetricSection.tsx`,
+`apps/desktop-tauri/src/surfaces/settings/providers/sections/charts/CostHistoryChart.tsx`,
+and relevant frontend tests.
+
+- Add German end-to-end through the existing `Language`, Fluent catalog, Rust
+  bridge, typed frontend key list, locale provider, tray text, FloatBar,
+  Settings, provider controls, and cost-history surfaces. Missing German keys
+  fail the existing key-completeness checks rather than silently rendering an
+  identifier.
+- Match the existing Windows Menu bar and Connection settings grouping. This
+  is grouping and copy parity in the current React/Tauri UI, not a recreation
+  of a Swift preferences form.
+- Add a rendered-content fingerprint for the cost-history chart so unchanged
+  rendered bars, labels, locale-formatted values, palette, and animation state
+  avoid redundant chart work. A changed accessible label or displayed value
+  must invalidate the fingerprint.
+- Cover German selection and representative tray/settings/provider strings,
+  grouping placement, and the equal-content/different-content chart cases.
+
+## Explicitly Non-Applicable Upstream Items
+
+The following upstream work is not ported because its Windows behavior is
+absent or already native:
+
+- Cursor WidgetKit widgets.
+- AppKit menu viewport restore.
+- Swift Form footer styling.
+- macOS Keychain pre-alert UI.
+- Website provider count and social card.
+- Sparkle appcast.
+- Unix foreground process-group PATH fix.
+
+## Review and Merge Gates
+
+For every PR:
+
+1. Start with focused failing tests, implement the smallest production change,
+   then retain regression coverage at the shared behavior boundary.
+2. Run applicable Rust, Tauri, frontend, locale, and build checks for the
+   touched surfaces.
+3. Require a correctness review before merge.
+
+PRs 2 and 3 additionally require a security review covering credential
+storage, fallback behavior, error text, logging, and secret propagation.
+
+After all seven PRs merge, run one combined thermo-nuclear code-quality review,
+Ponytail Review, Ponytail Audit, and Ponytail Debt. Fix every actionable
+finding before release.
+
+## Release Gate
+
+Release follows all seven merged PRs:
+
+1. Smoke-test the Windows installer and portable artifact.
+2. Perform CUA across tray, FloatBar, every Settings tab, provider controls,
+   German, and cost history.
+3. Open a release PR that bumps the Windows version to 0.42.1.
+4. Publish four release assets and verify their hashes and downloads.
+5. Submit and validate the immutable Winget 0.42.1 manifest.
+
+## Self-Review
+
+This specification has seven focused, behavior-only PRs; PR 5 explicitly
+depends on PR 1 and is paired with PR 3 review, and release explicitly
+depends on all seven. The required literal concepts are defined with their
+acceptance/rejection semantics, target paths, review gates, and Windows-only
+scope. All existing target paths were verified in this checkout; the two
+explicitly marked new modules are planned additions. No unresolved work markers
+are present; the word "placeholder" appears only where the required
+synthetic-placeholder behavior is specified.