Align plan-review e2e + UI with the HEAD (pre-#1635) backend

The merge left a split plan vertical: the backend save_plan/plan_api are
HEAD (we deferred the editable-plan/sandbox-publish features #1610/#1635/
#1637 per #80), but the plan UI and e2e harness were upstream's. The
fake_llm scenario called save_plan(plan_file_path=...) — upstream's
file-based #1635 contract — while HEAD save_plan takes plan_markdown,
so the plan never saved and PlanReview never rendered (E2E failure on
the plan-review locator).

Pass plan_markdown to save_plan, and revert PlanReview.tsx / plan.ts /
$threadId_.plan.tsx / plan_review.spec.ts to the dev baseline so the
whole plan flow (save -> render -> approve -> implement) is consistent
with the HEAD backend.

tests/e2e/fake_llm.py

@@ -226,7 +226,7 @@ def _save_plan_step(_messages: list[BaseMessage]) -> AIMessage:
         tool_calls=[
             {
                 "name": "save_plan",
-                "args": {"plan_file_path": PLAN_FILE_PATH},
+                "args": {"plan_markdown": PLAN_MARKDOWN},
                 "id": "call-save-plan",
             }
         ],

tests/e2e/tests/plan_review.spec.ts

@@ -126,11 +126,10 @@ test.describe("Plan review (HTTP comments)", () => {
     await addComment(collab, "Reviewer: please also add a docstring.");
     await expect(collab.getByTestId("plan-comment")).toHaveCount(2);
 
-    // 5. The owner sees the collaborator's comment (polled), then approves and
-    //    returns to the main conversation while implementation starts.
+    // 5. The owner sees the collaborator's comment (polled), then approves.
     await expect(owner.getByTestId("plan-comment")).toHaveCount(2, { timeout: 30_000 });
     await owner.getByTestId("approve-plan").click();
-    await expect(owner).toHaveURL(new RegExp(`/agents/${threadId}$`));
+    await expect(owner.getByTestId("plan-decision")).toContainText(/implementing/i);
 
     // 6. The agent implements, opens a PR, and links it back in the Slack thread,
     //    echoing the reviewers' feedback — which proves the comments were stored

ui/src/components/agents/PlanReview.tsx

@@ -1,5 +1,4 @@
 import { useCallback, useEffect, useState } from "react"
-import { useNavigate } from "@tanstack/react-router"
 
 import type { PlanComment, PlanData } from "@/lib/plan"
 import {
@@ -8,7 +7,6 @@ import {
   deletePlanComment,
   getPlanComments,
   rejectPlan,
-  updatePlan,
 } from "@/lib/plan"
 import { Button } from "@/components/ui/button"
 import { Markdown } from "@/components/agents/ported"
@@ -49,7 +47,6 @@ async function copyToClipboard(text: string): Promise<boolean> {
 }
 
 export function PlanReview({ plan }: { plan: PlanData }) {
-  const navigate = useNavigate()
   const resolvedTheme = useResolvedTheme()
   const [comments, setComments] = useState<Array<PlanComment>>([])
   const [draft, setDraft] = useState("")
@@ -58,50 +55,6 @@ export function PlanReview({ plan }: { plan: PlanData }) {
   const [busy, setBusy] = useState<"approve" | "reject" | null>(null)
   const [error, setError] = useState<string | null>(null)
   const [copied, setCopied] = useState(false)
-  // Locally track the displayed markdown so a manual edit shows immediately; the
-  // route's query stops polling once a plan exists, so the prop won't refetch.
-  const [markdown, setMarkdown] = useState(plan.markdown)
-  const [editing, setEditing] = useState(false)
-  const [editDraft, setEditDraft] = useState(plan.markdown)
-  const [saving, setSaving] = useState(false)
-
-  // Reflect external plan updates (e.g. an agent revision) while not editing.
-  useEffect(() => {
-    if (!editing) setMarkdown(plan.markdown)
-  }, [plan.markdown, editing])
-
-  const canEdit =
-    plan.isOwner && plan.status !== "approved" && plan.status !== "cancelled"
-
-  const startEditing = useCallback(() => {
-    setEditDraft(markdown)
-    setEditing(true)
-    setError(null)
-  }, [markdown])
-
-  const cancelEditing = useCallback(() => {
-    setEditing(false)
-    setError(null)
-  }, [])
-
-  const saveEdit = useCallback(async () => {
-    const next = editDraft.trim()
-    if (!next) {
-      setError("The plan cannot be empty.")
-      return
-    }
-    setSaving(true)
-    setError(null)
-    try {
-      const result = await updatePlan(plan.threadId, next)
-      setMarkdown(result.markdown)
-      setEditing(false)
-    } catch (e) {
-      setError((e as Error).message)
-    } finally {
-      setSaving(false)
-    }
-  }, [editDraft, plan.threadId])
 
   // Poll so reviewers see each other's comments without a realtime transport.
   useEffect(() => {
@@ -155,42 +108,39 @@ export function PlanReview({ plan }: { plan: PlanData }) {
       setBusy(kind)
       setError(null)
       try {
-        if (kind === "approve") {
-          await approvePlan(plan.threadId)
-          await navigate({
-            to: "/agents/$threadId",
-            params: { threadId: plan.threadId },
-          })
-          return
-        }
-        await rejectPlan(plan.threadId)
-        setDecision("Changes requested — the agent is revising the plan.")
+        if (kind === "approve") await approvePlan(plan.threadId)
+        else await rejectPlan(plan.threadId)
+        setDecision(
+          kind === "approve"
+            ? "Plan approved — the agent is implementing it."
+            : "Changes requested — the agent is revising the plan."
+        )
       } catch (e) {
         setError((e as Error).message)
       } finally {
         setBusy(null)
       }
     },
-    [navigate, plan.threadId]
+    [plan.threadId]
   )
 
   const copyPlan = useCallback(async () => {
     setError(null)
-    if (await copyToClipboard(markdown)) {
+    if (await copyToClipboard(plan.markdown)) {
       setCopied(true)
       window.setTimeout(() => setCopied(false), 1500)
     } else {
       setError("Couldn't copy the plan to the clipboard.")
     }
-  }, [markdown])
+  }, [plan.markdown])
 
   return (
     <div
       data-testid="plan-review"
       className="flex min-h-0 flex-1 flex-col bg-[var(--ui-bg)] text-[var(--ui-text)]"
     >
-      <div className="flex flex-col gap-3 border-b border-[var(--ui-border)] px-4 py-3 md:flex-row md:items-center md:justify-between md:gap-4 md:px-6">
-        <div className="min-w-0">
+      <div className="flex items-center justify-between gap-4 border-b border-[var(--ui-border)] px-6 py-3">
+        <div>
           <h1 className="text-base font-semibold text-[var(--ui-text)]">
             Implementation plan
           </h1>
@@ -200,105 +150,58 @@ export function PlanReview({ plan }: { plan: PlanData }) {
             <span data-testid="plan-status">{plan.status}</span>
           </p>
         </div>
-        <div className="flex min-w-0 flex-wrap items-center gap-2 md:shrink-0 md:justify-end">
+        <div className="flex shrink-0 items-center gap-2">
           {decision && (
             <span
               data-testid="plan-decision"
-              className="w-full text-xs text-[var(--ui-text-dim)] md:w-auto"
+              className="text-xs text-[var(--ui-text-dim)]"
             >
               {decision}
             </span>
           )}
-          {editing ? (
-            <>
-              <Button
-                data-testid="cancel-edit-plan"
-                variant="secondary"
-                disabled={saving}
-                onClick={cancelEditing}
-              >
-                Cancel
-              </Button>
-              <Button
-                data-testid="save-plan"
-                disabled={saving || !editDraft.trim()}
-                onClick={() => void saveEdit()}
-              >
-                {saving ? "Saving…" : "Save"}
-              </Button>
-            </>
-          ) : (
-            <>
-              {canEdit && (
-                <Button
-                  data-testid="edit-plan"
-                  variant="secondary"
-                  disabled={busy !== null || decision !== null}
-                  onClick={startEditing}
-                >
-                  Edit
-                </Button>
-              )}
-              <Button
-                data-testid="copy-plan"
-                variant="secondary"
-                disabled={!markdown.trim()}
-                onClick={() => void copyPlan()}
-              >
-                {copied ? "Copied!" : "Copy markdown"}
-              </Button>
-              {plan.isOwner && (
-                <Button
-                  data-testid="approve-plan"
-                  disabled={busy !== null || decision !== null}
-                  onClick={() => void decide("approve")}
-                >
-                  Approve
-                </Button>
-              )}
-              <Button
-                data-testid="reject-plan"
-                variant="secondary"
-                // Requesting changes feeds the comments to the agent, so it's
-                // meaningless with none — disable until at least one is left.
-                disabled={
-                  busy !== null || decision !== null || comments.length === 0
-                }
-                title={
-                  comments.length === 0
-                    ? "Leave a comment first to request changes"
-                    : undefined
-                }
-                onClick={() => void decide("reject")}
-              >
-                Request changes
-              </Button>
-            </>
+          <Button
+            data-testid="copy-plan"
+            variant="secondary"
+            disabled={!plan.markdown.trim()}
+            onClick={() => void copyPlan()}
+          >
+            {copied ? "Copied!" : "Copy markdown"}
+          </Button>
+          {plan.isOwner && (
+            <Button
+              data-testid="approve-plan"
+              disabled={busy !== null || decision !== null}
+              onClick={() => void decide("approve")}
+            >
+              Approve
+            </Button>
           )}
+          <Button
+            data-testid="reject-plan"
+            variant="secondary"
+            // Requesting changes feeds the comments to the agent, so it's
+            // meaningless with none — disable until at least one is left.
+            disabled={busy !== null || decision !== null || comments.length === 0}
+            title={
+              comments.length === 0
+                ? "Leave a comment first to request changes"
+                : undefined
+            }
+            onClick={() => void decide("reject")}
+          >
+            Request changes
+          </Button>
         </div>
       </div>
 
-      <div className="flex min-h-0 flex-1 flex-col overflow-y-auto md:flex-row md:overflow-hidden">
+      <div className="flex min-h-0 flex-1 overflow-hidden">
         <div
-          className="min-w-0 px-4 py-4 md:min-h-0 md:flex-1 md:overflow-auto md:px-6"
+          className="min-h-0 flex-1 overflow-auto px-6 py-4"
           data-testid="plan-document"
           data-color-scheme={resolvedTheme}
         >
-          {editing ? (
-            <div className="flex h-full flex-col gap-2">
-              {error && (
-                <p className="text-xs text-[color:var(--ui-danger)]">{error}</p>
-              )}
-              <textarea
-                data-testid="plan-editor"
-                value={editDraft}
-                onChange={(e) => setEditDraft(e.target.value)}
-                spellCheck={false}
-                className="min-h-[20rem] w-full flex-1 resize-none rounded-md border border-[var(--ui-border)] bg-[var(--ui-bg)] px-3 py-2 font-mono text-sm text-[var(--ui-text)] outline-none focus:border-[var(--ui-accent)]"
-              />
-            </div>
-          ) : markdown.trim() ? (
-            <Markdown content={markdown} />
+          {plan.markdown.trim() ? (
+            <Markdown content={plan.markdown} />
           ) : (
             <p className="text-sm text-[var(--ui-text-dim)]">
               The plan hasn't been written yet.
@@ -306,14 +209,14 @@ export function PlanReview({ plan }: { plan: PlanData }) {
           )}
         </div>
 
-        <aside className="flex shrink-0 flex-col border-t border-[var(--ui-border)] md:w-80 md:border-t-0 md:border-l">
+        <aside className="flex w-80 shrink-0 flex-col border-l border-[var(--ui-border)]">
           <div className="border-b border-[var(--ui-border)] px-4 py-3">
             <h2 className="text-sm font-semibold text-[var(--ui-text)]">
               Comments
             </h2>
           </div>
           <div
-            className="max-h-80 space-y-3 overflow-auto px-4 py-3 md:max-h-none md:min-h-0 md:flex-1"
+            className="min-h-0 flex-1 space-y-3 overflow-auto px-4 py-3"
             data-testid="plan-comments"
           >
             {comments.length === 0 ? (

ui/src/lib/plan.ts

@@ -113,16 +113,6 @@ export function deletePlanComment(
   )
 }
 
-export function updatePlan(
-  threadId: string,
-  markdown: string
-): Promise<{ status: PlanStatus; markdown: string }> {
-  return req(`/plan/${encodeURIComponent(threadId)}`, {
-    method: "PUT",
-    body: JSON.stringify({ markdown }),
-  })
-}
-
 export function approvePlan(threadId: string): Promise<{ status: string }> {
   return req(`/plan/${encodeURIComponent(threadId)}/approve`, {
     method: "POST",

ui/src/routes/agents/$threadId_.plan.tsx

@@ -13,7 +13,7 @@ export const Route = createFileRoute("/agents/$threadId_/plan")({
 
 function Centered({ children }: { children: React.ReactNode }) {
   return (
-    <div className="flex min-w-0 flex-1 items-center justify-center px-4 py-6 max-md:pt-14 md:p-6">
+    <div className="flex min-w-0 flex-1 items-center justify-center p-6">
       {children}
     </div>
   )
@@ -100,7 +100,7 @@ function PlanPage() {
 
   return (
     <div className="flex min-w-0 flex-1 flex-col">
-      <div className="border-b border-[var(--ui-border)] px-4 pt-14 md:px-6 md:pt-3">
+      <div className="border-b border-[var(--ui-border)] px-6 pt-3">
         <BackLink threadId={threadId} />
       </div>
       <PlanReview plan={plan} />