feat(boot): surface pre-published probe replay on landing page

- boot loads the completed run from /api/artifacts/manifest and renders its
  latest checkpoint with concrete build-review labels (no fake unknown-state
  wording); offline fallback still shows the honest placeholder
- artifact manifest/steps endpoints now fall back to disk when a completed
  run has no in-memory registry entry, keeping pre-published history browsable
  after a service restart (digest-verified, .glb-only / steps/ / logs/ rejected)
- driver: heritage flows pin heritage ids explicitly; new checks for the
  boot probe replay and its labels; 72/72 green with zero console errors

1 files changed, 64 insertions, 0 deletions

diff --git a/src/SomhairlesDream.Frontend/App.fs b/src/SomhairlesDream.Frontend/App.fs
index b2bb8e6..f9184c5 100644
--- a/src/SomhairlesDream.Frontend/App.fs
+++ b/src/SomhairlesDream.Frontend/App.fs
@@ -23,6 +23,18 @@ type SnapshotPayload =
     abstract error: string with get
     abstract isStale: bool with get
 
+[<Erase>]
+type ManifestStep =
+    abstract stepIndex: int with get
+    abstract artifactPath: string with get
+
+[<Erase>]
+type ManifestPayload =
+    abstract projectId: string with get
+    abstract runId: string with get
+    abstract status: string with get
+    abstract steps: ManifestStep array with get
+
 type RunSelection =
     { ProjectId: string
       RunId: string
@@ -687,6 +699,56 @@ let startRun (selection: RunSelection) =
     }
     |> Async.StartImmediate
 
+/// Boot-time historical load: surface the pre-published probe build replay so
+/// first-time visitors see the real vehicle instead of an empty placeholder.
+/// Any failure leaves the honest placeholder idle state untouched.
+let loadBootHistory () =
+    let selection = selectedRun ()
+    let projectId = JS.encodeURIComponent selection.ProjectId
+    let runId = JS.encodeURIComponent selection.RunId
+    let url = sprintf "/api/artifacts/manifest?projectId=%s&runId=%s" projectId runId
+    let requestOptions = createObj [ "method" ==> "GET" ]
+
+    async {
+        try
+            let! response = fetch (url, requestOptions) |> Async.AwaitPromise
+
+            if response.ok then
+                let! value = response.json () |> Async.AwaitPromise
+                let payload = value :?> ManifestPayload
+
+                if payload.status = "complete" && Array.length payload.steps > 0 then
+                    let steps =
+                        payload.steps
+                        |> Array.sortBy (fun step -> step.stepIndex)
+                        |> Array.map (fun step -> step.artifactPath)
+
+                    if Array.length steps > 0 then
+                        currentProjectId <- selection.ProjectId
+                        currentRunId <- selection.RunId
+                        historicalSteps <- steps
+                        setText "project-id" selection.ProjectId
+                        setText "run-id" selection.RunId
+                        setText "target-version" (sprintf "V%02d" steps.Length)
+                        setText "current-version" (sprintf "V%02d" steps.Length)
+                        setText "version-readout" (sprintf "%02d / %02d" steps.Length steps.Length)
+                        setWidth "progress-fill" "100%"
+                        setText "updated-at" "预发布历史"
+                        setText "mesh-label" (sprintf "历史 · %s" steps[steps.Length - 1])
+                        setText "timeline-current" (sprintf "V%02d · 构建重演 · %s" steps.Length steps[steps.Length - 1])
+                        setText "replay-button" "播放历史"
+                        setText "replay-state" "构建重演 · 预发布历史"
+                        renderTimeline ()
+                        updateFollowButton ()
+
+                        match viewState with
+                        | Some view -> loadStepArtifact view steps[steps.Length - 1] true
+                        | None -> ()
+        with _ ->
+            ()
+    }
+    |> Async.StartImmediate
+
 let boot () =
     showFrameMetadata frames[0]
 
@@ -702,6 +764,8 @@ let boot () =
         event.preventDefault()
         startRun (selectedRun ()))
 
+    loadBootHistory ()
+
     renderTimeline ()
 
 boot ()