Integration: merge into any lane, parent-head simulation, resolver instructions

apps/desktop/src/main/services/conflicts/conflictService.ts

@@ -3930,7 +3930,7 @@ export function createConflictService({
     ];
     const status: PrepareResolverSessionResult["status"] = contextGaps.length > 0 ? "blocked" : "ready";
 
-    const prompt = buildExternalResolverPrompt({
+    let prompt = buildExternalResolverPrompt({
       targetLaneId,
       sourceLaneIds,
       contexts,
@@ -3939,6 +3939,10 @@ export function createConflictService({
       integrationLaneId: integrationLane?.id ?? null,
       scenario
     });
+    const extra = typeof args.additionalInstructions === "string" ? args.additionalInstructions.trim() : "";
+    if (extra.length > 0) {
+      prompt += `\n\n---\n\n## Operator instructions\n\n${extra}\n`;
+    }
     const promptPath = path.join(runDir, "prompt.md");
     fs.writeFileSync(promptPath, prompt, "utf8");
 

apps/desktop/src/main/services/ipc/registerIpc.ts

@@ -4785,6 +4785,9 @@ export function registerIpc({
     const reasoning = typeof arg?.reasoning === "string" && arg.reasoning.trim().length > 0
       ? arg.reasoning.trim()
       : null;
+    const additionalInstructions = typeof arg?.additionalInstructions === "string" && arg.additionalInstructions.trim().length > 0
+      ? arg.additionalInstructions.trim()
+      : null;
     let runId = "";
 
     if (!model) {
@@ -4841,6 +4844,7 @@ export function registerIpc({
         model,
         reasoningEffort: reasoning,
         permissionMode,
+        additionalInstructions,
         originSurface: context.sourceTab === "integration"
           ? "integration"
           : context.sourceTab === "rebase"

apps/desktop/src/main/services/state/kvDb.missionsMigration.test.ts

@@ -81,6 +81,7 @@ describe("kvDb mission schema migration", () => {
         "integration_lane_name",
         "status",
         "integration_lane_id",
+        "preferred_integration_lane_id",
         "resolution_state_json",
         "pairwise_results_json",
         "lane_summaries_json"

apps/desktop/src/main/services/state/kvDb.ts

@@ -1161,6 +1161,7 @@ function migrate(db: { run: (sql: string, params?: SqlValue[]) => void }) {
   try { db.run("alter table integration_proposals add column completed_at text"); } catch {}
   try { db.run("alter table integration_proposals add column cleanup_declined_at text"); } catch {}
   try { db.run("alter table integration_proposals add column cleanup_completed_at text"); } catch {}
+  try { db.run("alter table integration_proposals add column preferred_integration_lane_id text"); } catch {}
 
   // Queue landing state table (crash recovery for sequential landing)
   db.run(`

apps/desktop/src/renderer/components/prs/CreatePrModal.tsx

@@ -505,6 +505,7 @@ export function CreatePrModal({
   const [integrationTitle, setIntegrationTitle] = React.useState("");
   const [integrationBody, setIntegrationBody] = React.useState("");
   const [integrationDraft, setIntegrationDraft] = React.useState(false);
+  const [integrationMergeIntoLaneId, setIntegrationMergeIntoLaneId] = React.useState("");
   const [proposal, setProposal] = React.useState<IntegrationProposal | null>(null);
   const [simulating, setSimulating] = React.useState(false);
   const [laneSyncStatusById, setLaneSyncStatusById] = React.useState<Record<string, GitUpstreamSyncStatus | null>>({});
@@ -622,6 +623,7 @@ export function CreatePrModal({
       setDraftError(null);
       setIntegrationSources([]);
       setIntegrationBaseBranch("");
+      setIntegrationMergeIntoLaneId("");
       setIntegrationName("");
       setIntegrationTitle("");
       setIntegrationBody("");
@@ -715,9 +717,15 @@ export function CreatePrModal({
     try {
       const trimmedIntegrationBaseBranch = integrationBaseBranch.trim();
       const baseBranch = trimmedIntegrationBaseBranch || branchNameFromRef(primaryLane?.branchRef ?? "main");
+      const mergeInto = integrationMergeIntoLaneId.trim();
+      if (mergeInto && integrationSources.includes(mergeInto)) {
+        setExecError("Merge-into lane cannot be one of the source lanes.");
+        return;
+      }
       const result = await window.ade.prs.simulateIntegration({
         sourceLaneIds: integrationSources,
         baseBranch,
+        mergeIntoLaneId: mergeInto || null,
       });
       setProposal(result);
       // Auto-generate a name if empty
@@ -784,6 +792,7 @@ export function CreatePrModal({
           body: integrationBody,
           draft: integrationDraft,
           integrationLaneName: integrationName || `integration/${Date.now().toString(36)}`,
+          preferredIntegrationLaneId: integrationMergeIntoLaneId.trim() || null,
         });
         lastProgressLabel = "Creating integration lane";
         setIntegrationProgress("Creating integration lane...");
@@ -812,6 +821,19 @@ export function CreatePrModal({
 
   const nonPrimaryLanes = React.useMemo(() => lanes.filter((l) => l.laneType !== "primary"), [lanes]);
 
+  const integrationMergeIntoOptions = React.useMemo(
+    () => [...nonPrimaryLanes].sort((a, b) => a.name.localeCompare(b.name)),
+    [nonPrimaryLanes],
+  );
+
+  React.useEffect(() => {
+    if (!integrationMergeIntoLaneId) return;
+    if (integrationSources.includes(integrationMergeIntoLaneId)) {
+      setIntegrationMergeIntoLaneId("");
+      setProposal(null);
+    }
+  }, [integrationMergeIntoLaneId, integrationSources]);
+
   const toggleQueueLane = (laneId: string) => {
     setQueueLaneIds((prev) =>
       prev.includes(laneId) ? prev.filter((id) => id !== laneId) : [...prev, laneId]
@@ -1499,6 +1521,37 @@ export function CreatePrModal({
                       />
                     </div>
 
+                    <div>
+                      <span style={labelStyle}>MERGE INTO (OPTIONAL)</span>
+                      <select
+                        aria-label="Merge integration into existing lane"
+                        value={integrationMergeIntoLaneId}
+                        onChange={(e) => {
+                          setIntegrationMergeIntoLaneId(e.target.value);
+                          setProposal(null);
+                        }}
+                        style={selectStyle}
+                        onFocus={(ev) => { ev.currentTarget.style.borderColor = C.accent; }}
+                        onBlur={(ev) => { ev.currentTarget.style.borderColor = C.borderSubtle; }}
+                      >
+                        <option value="">New integration branch</option>
+                        {integrationMergeIntoOptions.map((lane) => (
+                          <option key={lane.id} value={lane.id} disabled={integrationSources.includes(lane.id)}>
+                            {lane.name}{integrationSources.includes(lane.id) ? " (source)" : ""}
+                          </option>
+                        ))}
+                      </select>
+                      <div style={{
+                        marginTop: 6,
+                        fontSize: 10,
+                        fontFamily: "var(--font-sans)",
+                        color: C.textMuted,
+                        lineHeight: "14px",
+                      }}>
+                        When set, simulation includes conflicts against that lane&apos;s current HEAD. Commit prepares merges there instead of creating a new lane.
+                      </div>
+                    </div>
+
                     {/* Simulate button */}
                     <div style={{ display: "flex", alignItems: "center", gap: 10 }}>
                       <button

apps/desktop/src/renderer/components/prs/shared/PrAiResolverPanel.tsx

@@ -37,6 +37,8 @@ type PrAiResolverPanelProps = {
   startLabel?: string;
   defaultExpanded?: boolean;
   sessionShellClassName?: string;
+  /** Optional notes appended to the generated resolver prompt (e.g. “keep UI from lane A”). */
+  showResolverInstructions?: boolean;
 };
 
 function normalizeReasoning(value: string): string | null {
@@ -91,12 +93,14 @@ export function PrAiResolverPanel({
   startLabel = "Start AI Resolver",
   defaultExpanded = true,
   sessionShellClassName,
+  showResolverInstructions = false,
 }: PrAiResolverPanelProps) {
   const { resolverSessionsByContextKey, upsertResolverSession } = usePrs();
   const [launching, setLaunching] = React.useState(false);
   const [status, setStatus] = React.useState<"idle" | "starting" | "running" | "completed" | "failed" | "cancelled">("idle");
   const [message, setMessage] = React.useState<string | null>(null);
   const [expanded, setExpanded] = React.useState(defaultExpanded);
+  const [resolverInstructions, setResolverInstructions] = React.useState("");
   const terminalStatusRef = React.useRef<PrAiResolverCompletion["status"] | null>(null);
   const contextKey = React.useMemo(() => (context ? buildPrAiResolutionContextKey(context) : null), [context]);
   const activeSession = React.useMemo(
@@ -117,6 +121,10 @@ export function PrAiResolverPanel({
     }
   }, [activeSession]);
 
+  React.useEffect(() => {
+    setResolverInstructions("");
+  }, [contextKey]);
+
   React.useEffect(() => {
     if (!context || !contextKey || activeSession) return;
     let cancelled = false;
@@ -173,11 +181,13 @@ export function PrAiResolverPanel({
     setStatus("starting");
     terminalStatusRef.current = null;
     try {
+      const trimmedInstructions = resolverInstructions.trim();
       const result = await window.ade.prs.aiResolutionStart({
         model: displayModelId,
         reasoning: normalizeReasoning(displayReasoning),
         permissionMode: displayPermissionMode,
         context,
+        ...(trimmedInstructions ? { additionalInstructions: trimmedInstructions } : {}),
       });
       if (result.status !== "started") {
         setStatus("failed");
@@ -208,6 +218,7 @@ export function PrAiResolverPanel({
     displayReasoning,
     launching,
     onStarted,
+    resolverInstructions,
     upsertResolverSession,
   ]);
 
@@ -262,6 +273,21 @@ export function PrAiResolverPanel({
 
       {expanded ? (!sessionId ? (
         <div className="space-y-4 px-4 py-4">
+          {showResolverInstructions ? (
+            <div className="space-y-1.5">
+              <label className="block font-mono text-[9px] font-bold uppercase tracking-wider text-fg/50">
+                Resolver instructions (optional)
+              </label>
+              <textarea
+                value={resolverInstructions}
+                onChange={(e) => setResolverInstructions(e.target.value)}
+                placeholder="e.g. Prefer UI from the first lane; keep server logic from the second."
+                rows={3}
+                disabled={launching}
+                className="w-full resize-y border border-border/20 bg-bg/60 px-3 py-2 font-mono text-[11px] leading-relaxed text-fg/85 placeholder:text-fg/35 focus:border-border/40 focus:outline-none"
+              />
+            </div>
+          ) : null}
           <div className="flex flex-wrap items-center gap-3">
             <PrResolverLaunchControls
               modelId={displayModelId}