[Story]: Visual save-button state for unsaved changes

[adoLime]

User Story

As a user, I want every Save button to clearly reflect whether I have unsaved changes, so that I can see at a glance whether my edits have been persisted or still need saving.

Context & Motivation

• Type: Functional (UX consistency)
• Parent epic: 12 EPIC - UX, Documentation & Pilot Release #63 (12 EPIC – UX, Documentation & Pilot Release)
• Teams: team:frontend

Acceptance Criteria

• Save buttons are disabled / visually muted when there are no unsaved changes, and become enabled / highlighted as soon as the user edits any related field.
• State is not conveyed by color alone, paired with a text label and/or icon (accessibility).
• On successful save, the button returns to the "no unsaved changes" state.
• Loading ("Saving…"), error, and success feedback is preserved.
• Pattern is applied consistently to every Save button in the app.
• Works in light and dark themes; keyboard focus remains visible.