fix(tokens): input border color and radius tokens (before-next) (#31469)

Issue number: internal

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## What is the new behavior?

Port of #31468 (merged on `next`) to `before-next`.

- Input outline variant: border color now uses
`$ion-border-input-default` instead of `$ion-primitives-neutral-500`.
- Input soft shape variant: border radius now uses `$ion-shape-soft-lg`
instead of `$ion-shape-soft-xl`.

Snapshots are not copied from `next`, since they were generated against
a different input implementation. They need to be regenerated on this
branch with the "Update Reference Screenshots" workflow (component:
`input`).

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
Co-authored-by: ionitron <hi@ionicframework.com>

Author: 3 people

core/src/components/input-password-toggle/test/basic/input-password-toggle.e2e.ts-snapshots/input-password-toggle-ionic-md-ltr-light-Mobile-Chrome-linux.png

@@ -2,5 +2,5 @@
 
 :host(.input-fill-outline) {
   --background: #{globals.$ion-bg-surface-default};
-  --border-color: #{globals.$ion-primitives-neutral-500};
+  --border-color: #{globals.$ion-border-input-default};
 }

core/src/components/input-password-toggle/test/basic/input-password-toggle.e2e.ts-snapshots/input-password-toggle-ionic-md-ltr-light-Mobile-Firefox-linux.png

@@ -139,7 +139,7 @@
 // --------------------------------------------------
 
 :host(.input-shape-soft) {
-  --border-radius: #{globals.$ion-shape-soft-xl};
+  --border-radius: #{globals.$ion-shape-soft-lg};
 }
 
 :host(.input-shape-round) {