feat: consolidate database management work

Add catalog-owned logical relationships and runtime snapshots, extend the database-management UI and validation coverage, and document the updated operational workflow.

Keep active sensitive-generation status in a tooltip and indicator, and update the layout E2E to follow the history action in its new database-scoped location.

DESIGN.md

@@ -12,6 +12,10 @@ colors:
   muted-graphite: "oklch(51.33% 0.0088 345.6)"
   quiet-border: "oklch(90.93% 0.0035 354.7)"
   success-mint: "oklch(75.77% 0.1581 165)"
+  navigation-active: "oklch(92.5% 0.052 23.2)"
+  navigation-active-hover: "oklch(89.5% 0.071 23.2)"
+  navigation-active-foreground: "oklch(36.5% 0.11 23.2)"
+  navigation-active-border: "oklch(60% 0.135 23.2)"
   warning-amber: "oklch(85.23% 0.1386 78.9)"
   information-blue: "oklch(70.35% 0.1128 221.3)"
 typography:
@@ -152,8 +156,8 @@ frontend uses OKLCH tokens directly.
 
 ### Primary
 
-- **Instrument Red** (`instrument-red`): primary actions, current selection, focus identity, and
-  destructive meaning where the context already makes the action explicit.
+- **Instrument Red** (`instrument-red`): primary actions, focus identity, and destructive meaning
+  where the context already makes the action explicit.
 - **Instrument Red Pressed** (`instrument-red-hover`): hover and active emphasis for the primary
   action family.
 
@@ -170,6 +174,9 @@ frontend uses OKLCH tokens directly.
 ### Semantic
 
 - **Success Mint** (`success-mint`): completed and ready states.
+- **Navigation Active** (`navigation-active`): the one application surface currently in the
+  foreground. It shares Instrument Red's hue but uses a lighter, lower-chroma fill, so location is
+  visible without carrying the full weight of a primary action.
 - **Warning Amber** (`warning-amber`): waiting, attention, and in-progress states.
 - **Information Blue** (`information-blue`): informational state when red would imply action.
 
@@ -272,15 +279,44 @@ default, hover, focus, active, disabled, loading, and error behavior where those
 - **Focus:** three-pixel Instrument Red ring with a clear border shift.
 - **Error / Disabled:** errors combine destructive color with explanatory text; disabled controls
   retain readable contrast and use 50 percent opacity.
+- **Metadata catalog model:** Database Management keeps one compact, installation-level
+  metadata-generation LLM selector in the application header. The selection persists across
+  database, table, column, and relationship views; when no usable profile is configured, the
+  disabled control explains: “No metadata-generation LLM model is configured for this installation.”
 
 ### Navigation
 
 - **Style:** compact session rows use `8px` corners and restrained vertical padding.
-- **Default / Hover / Active:** transparent at rest, Sunken Surface on hover, and the same surface
-  with stronger text weight when active.
+- **Default / Hover / Active:** porcelain at rest, Sunken Surface on hover, and a muted Navigation
+  Active red with a defined border when current. Exactly one top-level navigation control is current.
+- **Administrative controls:** the admin-only Administration accordion groups Database management,
+  a structural divider, Workspace management, and Pi management in that order. Its trigger exposes
+  expanded state and starts collapsed by default, while non-admin users do not receive the accordion
+  or its navigation actions.
 - **Responsive:** collapse navigation structurally at the application breakpoint. Do not shrink
   labels into illegibility.
 
+### Tabs
+
+- **Shape:** compact label tabs sit on a shared baseline with rounded top corners and a two-pixel
+  lower edge. Inactive labels retain a complete Quiet Border and Porcelain Card surface, so every
+  label reads as a tab before interaction; hover feedback reinforces clickability.
+- **Current:** the selected tab uses the muted Navigation Active red for its fill, text, and defined border.
+  It must expose `aria-selected`, participate in a labelled `tablist`/`tabpanel`, and be the only
+  tab in the roving keyboard tab order.
+- **Keyboard:** Left/Right move between adjacent tabs with wrapping; Home/End select the first or
+  last tab.
+
+### Tooltips
+
+- **Row actions:** icon-action tooltips open three pixels below the trigger and align to its trailing
+  edge, so they never cover the icon row. They use a dark slate surface, porcelain text, and a
+  defined border rather than the light popover treatment.
+- **Interaction:** tooltip layers never receive pointer events. They appear on hover and keyboard
+  focus with a short ease-out transition, while the icon button keeps its complete accessible name.
+- **Scope:** this treatment is shared by database, table, column, and relationship row actions.
+  Toolbar and navigation hints may use separate collision-aware placement.
+
 ### Curated Evidence Documents
 
 Curated evidence follows a fixed reading order: title, compact type and purpose summary, scope,