Add permanent table index rail layout

docs/tables_frontend_overhaul_implementation_plan.md

@@ -62,6 +62,7 @@ It is intentionally implementation-focused:
 | 2026-03-21 | Post-P2 fix 2 | Completed | Rebuilt the shell omnibox as a dedicated command palette instead of a repurposed drawer, with shell-owned overlay markup, explicit viewport-safe geometry, autofocus, Escape and navigation close behavior, and a stable scrollable result body. |
 | 2026-03-21 | Post-P2 fix 3 | Completed | Moved omnibox overlay ownership from the header subtree into `AppShell` itself via a shared omnibox state service and a top-level palette host, which restored full-screen backdrop coverage and reliable outside-click close behavior. |
 | 2026-03-21 | P3.1 | Completed | Split `Tables.razor` into focused table components for the selector header, context bar, canvas, and legend while leaving loading, deep-link synchronization, and dialog state in the page host. |
+| 2026-03-21 | P3.2 | Completed | Replaced the floating table picker with a permanent left-rail layout, converted the old selector component into a real page header, and kept the current selection flow intact inside the new reference frame. |
 
 ### Lessons Learned
 
@@ -93,6 +94,7 @@ It is intentionally implementation-focused:
 - A command palette is not just a styled drawer. It needs shell-owned geometry, predictable focus behavior, and a bounded scroll region; treating it as a generic side panel led directly to the layout regressions found in Phase 2.
 - Backdrop and outside-click behavior depend on overlay ownership as much as CSS. If the trigger owns the overlay inside a sticky header subtree, fixed-position assumptions can break; shell-level overlays should be rendered by the shell, not by individual header controls.
 - The `Tables` rewrite is safer when orchestration and rendering are separated early. Keeping loading, persistence, and dialog state in the page host while extracting render-only components makes later layout and interaction changes much lower risk.
+- The `Tables` navigation model needs its own persistent geometry before advanced behaviors land. Converting the selector to a real rail first keeps later search and keyboard work from being tangled up with another structural rewrite.
 
 ## Target Outcomes
 
@@ -454,7 +456,7 @@ Build the shared interaction infrastructure needed by multiple destinations befo
 | Task | Status | Notes |
 | --- | --- | --- |
 | `P3.1` | Completed | `Tables.razor` now acts as the stateful host while selector/header/canvas/legend rendering lives in dedicated `Components/Tables` components. |
-| `P3.2` | Pending | Replace the selector dropdown shell with the permanent left rail layout. |
+| `P3.2` | Completed | The old dropdown picker is gone; `/tables` now uses a permanent left rail and a real page header while keeping the current selection flow intact. |
 | `P3.3` | Pending | Add search, keyboard navigation, pinned/recent sections, curated percentage chips, and family filtering to the rail. |
 | `P3.4` | Pending | Introduce the sticky context bar with roll jump and mode/filter controls. |
 | `P3.5` | Pending | Rework the canvas for sticky headers, sticky roll bands, stronger reading emphasis, and density control. |