feat(workspace,smart-scroll): per-conversation cwd + LSP view; smart auto-scroll

workspace ([email protected]): a cwd field in the Model sidebar view (GET/PUT /conversations/:id/cwd) + a new 'Language Servers' view (GET /conversations/:id/lsp) with per-server connected/starting/error badges, spinner, error text, and refresh. Store-owned reactive cwd, re-seeded on focus change; works for DRAFTS too (targets the draft's client-minted id, which survives promotion, so turn 1 runs in the chosen cwd). Network seam normalizes the untyped LSP body.

smart-scroll: pure stick-to-bottom reducer + injected controller shell (scroll/scrollend + a ResizeObserver on the content so the view follows async height changes — markdown/highlight, images, collapses, viewport reflow), plus a floating scroll-to-bottom button. FIX: restore the transcript scrollbar — the refactor moved overflow-y-auto to an inner child, so the flex-1 container needed min-h-0 to constrain instead of growing to content.

harness: vitest-setup polyfills Element.scrollTo + ResizeObserver (jsdom implements neither), fixing App component tests. docs: backend-handoff pruned (CR-3 resolved/removed); added cwd/LSP verification courier (backend confirmed all 6 asks ✅); removed the resolved cache-warming-timer courier.

Verified: svelte-check 0 errors, biome clean, 523 tests pass, vite build OK.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/app/App.test.ts b/src/app/App.test.ts
index 1534d1c..d22f84b 100644
--- a/src/app/App.test.ts
+++ b/src/app/App.test.ts
@@ -62,6 +62,14 @@ function fakeFetchImpl(): typeof fetch {
 				status: 200,
 			});
 		}
+		if (url.endsWith("/cwd")) {
+			return new Response(JSON.stringify({ conversationId: "c", cwd: null }), { status: 200 });
+		}
+		if (url.endsWith("/lsp")) {
+			return new Response(JSON.stringify({ conversationId: "c", cwd: null, servers: [] }), {
+				status: 200,
+			});
+		}
 		return new Response(JSON.stringify({ chunks: [], latestSeq: 0 }), { status: 200 });
 	};
 }