Realign search, clipboard, and lane-hover code with the second batch

Creation now clears the search by mechanism, not gesture: one seam
(noteUserCreation) states 04's rule once, called from the placeholder
funnel, paste — cards and lanes, after the staleness guard so a stale
paste clears nothing — and Finder file-drop creation; the attach path
deliberately doesn't clear, and cross-board arrivals and New Lane stay
outside the seam (a transfer isn't creation; a lane can't be born
invisible). An open inline rename now survives the filter hiding its
card: the model already kept the editor, but the field renders in the
card's slot, so renderedCards keeps the renaming card's slot exactly as
long as the editor is open — the query stands throughout, and commit or
Escape lets the predicate apply in the same pass. Verified conformant
and newly pinned: query-emptied lanes keep their slot with a 0 badge,
pasteboard staleness (takeover before paste and mid-staging both no-op),
out-transition reachability and the strip pre-divide hold by
construction with comments citing their rulings.

Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY

KanbanTests/FileDropWriteTests.swift

@@ -142,6 +142,24 @@ struct ImportAttachmentsToCardTests {
         #expect(store.banners.oneShots.isEmpty)
     }
 
+    /// **Attaching is not creating, so the query stands** (04-interactions.md § Search): the
+    /// carve-out is for an item that would otherwise be born invisible, and a drop on a card mints
+    /// nothing. Its twin — the *create* half clearing — is `creatingFromFilesClearsTheSearch` below.
+    @Test("A drop that only attaches leaves the search exactly where it was")
+    func attachingLeavesTheSearch() throws {
+        let fixture = try makeBoard()
+        defer { fixture.tearDown() }
+        let sources = try DropSources()
+        defer { sources.tearDown() }
+        let store = try BoardStore(rootURL: fixture.root)
+        let shot = try sources.file("shot.png")
+
+        store.searchQuery = "first"
+        store.importAttachments([shot], toCard: card1)
+
+        #expect(store.searchQuery == "first")
+    }
+
     @Test("A name already taken is renamed Finder-style rather than overwritten")
     func collisionsRename() throws {
         let fixture = try makeBoard()
@@ -415,6 +433,43 @@ struct CreateCardsFromFilesTests {
         #expect(store.banners.oneShots.count == 1)
         #expect(store.banners.oneShots.first?.error.operation == .importAttachment(filename: "gone.png"))
     }
+
+    /// **The create half is a user-initiated creation, so it clears the query** (04-interactions.md
+    /// § Search, stated by mechanism: "⌘N, Return-creation, the header button, empty-space
+    /// double-click, paste, and Finder file drops alike"). The card is titled `shot`, which the
+    /// standing query would hide — the whole point of the carve-out.
+    @Test("A file drop that creates cards clears the search — the same rule ⌘N obeys")
+    func creatingFromFilesClearsTheSearch() throws {
+        let fixture = try makeBoard()
+        defer { fixture.tearDown() }
+        let sources = try DropSources()
+        defer { sources.tearDown() }
+        let store = try BoardStore(rootURL: fixture.root)
+        let shot = try sources.file("shot.png")
+
+        store.searchQuery = "first"
+        store.createCards(fromFiles: [shot], inLane: lane1, at: 1)
+
+        #expect(store.searchQuery.isEmpty)
+    }
+
+    /// The other side of the same rule: a drop that creates nothing clears nothing. A destination the
+    /// reload took away is not a creation either — nothing was minted, so nothing could be born
+    /// invisible.
+    @Test("A drop with no destination creates nothing and leaves the query standing")
+    func aRefusedCreateLeavesTheSearch() throws {
+        let fixture = try makeBoard()
+        defer { fixture.tearDown() }
+        let sources = try DropSources()
+        defer { sources.tearDown() }
+        let store = try BoardStore(rootURL: fixture.root)
+        let shot = try sources.file("shot.png")
+
+        store.searchQuery = "first"
+        store.createCards(fromFiles: [shot], inLane: ItemID(rawValue: "no-such-lane"), at: 0)
+
+        #expect(store.searchQuery == "first")
+    }
 }
 
 // MARK: - Folders, refused