refactor: optimize onboarding - #2138

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/components/OnboardingProgress/index.tsx`:
- Around line 59-60: The ringColor and ringTrack variable assignments on lines
59-60 in the OnboardingProgress component use hardcoded color values (`#ffffff`
and rgba(255,255,255,0.28)) instead of theme tokens. Replace these hardcoded
color values with appropriate theme tokens from src/theme/variable.css following
the existing theme system pattern used elsewhere in the codebase. Ensure both
the white color and the white color with transparency values use theme variables
instead of magic color values.

In `@src/components/OnboardingProgress/style.less`:
- Around line 72-88: Replace all hardcoded white color values in the onboarding
badge styles with theme variables from src/theme/variable.css. Specifically,
update the .n9e-onboarding-badge-collapsed.is-custom-bg selector and its :hover
state to use theme variables instead of rgba(255, 255, 255, ...) for the
border-color and background properties, and update the color property in
.n9e-onboarding-badge-label and .n9e-onboarding-badge-count selectors to use a
theme variable instead of the hardcoded `#fff` value. Refer to the existing theme
variables in src/theme/variable.css to identify the appropriate replacements for
the various opacity levels used throughout this block.

In `@src/pages/landing/locale/zh_CN.ts`:
- Around line 3-16: In the zh_CN.ts locale file, the onboarding object has a
formatting inconsistency where the dismiss and hostTrack properties are placed
on the same line with only whitespace between them. Separate these two
properties by placing hostTrack on its own line (line 8) so that each property
in the onboarding object follows the consistent single-property-per-line
formatting convention used throughout the file and other locale files.

In `@src/pages/landing/style.less`:
- Around line 1633-1637: The `.n9e-landing-onboarding-node-done` class uses a
hardcoded color value `#fff` for the text color, which violates the project's
theme token guidelines. Replace the hardcoded white color in the color property
with an appropriate theme token variable from `src/theme/variable.css` that
represents white or light text color in the existing theme system, ensuring
consistency with other color values in the stylesheet that use theme variables.

---

Nitpick comments:
In `@src/components/OnboardingProgress/useOnboardingProgress.ts`:
- Line 41: Replace the TypeScript `any[]` cast with a runtime `Array.isArray()`
guard on the dashboard property assignment in the useOnboardingProgress hook.
Instead of casting `dashboardRes.value as any[]` and then accessing its length,
use `Array.isArray(dashboardRes.value)` as a conditional check to verify the
value is an actual array before accessing its length property. This eliminates
the unsafe `any` type cast while maintaining the same runtime validation and
preserving type safety according to the coding guidelines.

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/components/OnboardingProgress/useOnboardingProgress.ts`:
- Around line 27-33: The logout handler has a fallback path using
history.push('/login') for client-side navigation that does not reload the page,
which leaves the module-level lastDetect variable and the sessionStorage
ONBOARDING_DONE_KEY in their previous state. When the fallback path executes
instead of the full page reload path, explicitly clear both the sessionStorage
entry (using sessionStorage.removeItem with ONBOARDING_DONE_KEY) and reset the
lastDetect variable to its initial state (with all properties set to false)
before calling history.push('/login') to prevent a new user from inheriting the
previous user's onboarding completion state.

In `@src/pages/hosts/pages/List/List.tsx`:
- Around line 391-398: The bare <a> tag with onClick handler for openCategrafDoc
on line 396 lacks an href attribute, making it inaccessible to keyboard users.
Replace this <a onClick={openCategrafDoc}>{t('categraf_doc')}</a> element with
an antd Button component using type='link' and the same onClick handler: <Button
type='link' onClick={openCategrafDoc}>{t('categraf_doc')}</Button>. This will
ensure the element is keyboard-focusable and can be activated using Enter or
Space keys.

---

Outside diff comments:
In `@src/components/OnboardingProgress/useOnboardingProgress.ts`:
- Around line 70-80: The hostDashboard and dashboard properties in the doneMap
object both rely on the same detect.dashboard signal, which causes hostDashboard
to be marked as complete whenever any dashboard exists, even if it's not a
host-specific dashboard. Fix this by updating the hostDashboard evaluation logic
to specifically verify that a built-in or host-specific dashboard was imported,
such as by checking board metadata, template identifier, or component type,
rather than just checking if detect.dashboard is true. Keep the machine check as
a gate, but add an additional condition that validates the dashboard is actually
a host dashboard before marking that step as done.

---

Nitpick comments:
In `@src/components/OnboardingProgress/useOnboardingProgress.ts`:
- Around line 56-68: The useEffect hook in the useOnboardingProgress function
re-runs the probeOnboarding function on every pathname change, causing expensive
endpoint calls to fire repeatedly for new users who haven't completed
onboarding. Implement a module-level caching mechanism with a short time-to-live
(TTL) to store the probing results and avoid unnecessary re-fetches when
pathname changes. Before calling probeOnboarding, check if cached results exist
and are still valid based on the TTL; only make a new probe call if the cache
has expired or doesn't exist. This will prevent the heavy endpoints mentioned in
probeOnboarding from being called excessively during navigation.