docs: session handoff 63 + ADR-0046 marked implemented (#20/#21/#23)

ADR-0046 status -> Accepted + implemented (8 commits 9f5f76b..22bec61);
README index updated; the two draft-divergent decisions recorded inline
(App.relationships not SchemaCache; nav overlay partial-clear + gutter).
Handoff 63 covers the full UI build across Phases A/B/C; issues
#20/#21/#23 closed on Gitea.

docs/adr/0046-sidebar-navigation-and-responsive-input-hint.md

@@ -2,12 +2,21 @@
 
 ## Status
 
-Accepted (2026-06-10); **implementation pending**, phased **A → B → C**
-(see *Decision — phasing*). Closes Gitea issues **#20** (hint-panel
-height jumpiness), **#21** (database-structure / left-column
-improvements), and **#23** (long command input). Issue #23's own note
-("handle after #21 is decided") is honoured: the input work is split so
-the part that depends on the sidebar's width budget lands with it.
+Accepted (2026-06-10); **implemented 2026-06-10**, phased **A → B → C**
+(see *Decision — phasing*) across commits `9f5f76b` (DA1/DA2) · `e0b9470`
+(DA3) · `41bae99` (DA4) · `386627a` (DB1) · `94825d0` (DB2/DB4) ·
+`c9da6ff` (DC1/DC2/DC4) · `22bec61` (DC3 + DC2 refinement). Closes Gitea
+issues **#20** (hint-panel height jumpiness), **#21** (database-structure
+/ left-column improvements), and **#23** (long command input). Issue
+#23's own note ("handle after #21 is decided") is honoured: the input
+work is split so the part that depends on the sidebar's width budget
+lands with it.
+
+Two decisions landed differently from the original draft and are
+recorded inline: the relationship data lives on **`App`, not
+`SchemaCache`** (DB2), and the navigation overlay clears **only the
+sidebar strip + a one-column gutter** (panels stay visible behind),
+not the whole area (DC2).
 
 Builds on and honours: **ADR-0003** (the persistent Simple/Advanced
 mode model — navigation mode is *not* a third input mode, see DC1),