Media build part 2 (unreleased): drive wiring in every app (R-1024/R-1037), old-install repair (R-1047), drive events notice + real restart now/later + stream check, file browser lets go of dead/removed drives and recreates on return (R-1038), safe removal keeps the drive (R-1044), Plex claim on the running server + probe accept (R-1028/R-1045)

Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

controller/internal/stacks/setup_gate.go

@@ -50,6 +50,9 @@ type SetupDoneProbe struct {
 	Done  string `yaml:"done" json:"done"`
 	// DoneStatus (v0.282.0, R-715): a non-200 HTTP status that itself means "set up" (gramps-web answers 405).
 	DoneStatus int `yaml:"done_status,omitempty" json:"done_status,omitempty"`
+	// Accept (v0.313.0, R-1028/R-1045): the Accept header the probe sends — Plex answers /identity in XML unless asked
+	// for JSON (measured 2026-10-15). Empty = no header (unchanged for every other app).
+	Accept string `yaml:"accept,omitempty" json:"accept,omitempty"`
 }
 
 // Setup gate states.
@@ -380,12 +383,33 @@ var setupGateProbeFetch = func(url string) (int, []byte, error) {
 	return resp.StatusCode, b, err
 }
 
+// setupGateProbeFetchAccept is setupGateProbeFetch with an Accept header (a seam too).
+var setupGateProbeFetchAccept = func(url, accept string) (int, []byte, error) {
+	c := &http.Client{Timeout: 5 * time.Second}
+	req, err := http.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		return 0, nil, err
+	}
+	req.Header.Set("Accept", accept)
+	resp, err := c.Do(req)
+	if err != nil {
+		return 0, nil, err
+	}
+	defer resp.Body.Close()
+	b, err := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	return resp.StatusCode, b, err
+}
+
 // probeOnce asks the app's own status once. v0.282.0 (R-715): `done_status:` — an app that answers a fixed non-200
 // status once it is set up (gramps-web: 405 "Users already exist") — counts as done on that status alone; any other
 // non-200 is "cannot read" (fail closed). A 200 is read as JSON: `field` is a dotted path whose parts may be list
 // indexes (`setup.0.status` — ghost; `0.done` — home-assistant), compared as text with `done`.
 func probeOnce(p *SetupDoneProbe) (done bool, got string, err error) {
-	status, body, err := setupGateProbeFetch(p.URL)
+	fetch := setupGateProbeFetch
+	if p.Accept != "" {
+		fetch = func(u string) (int, []byte, error) { return setupGateProbeFetchAccept(u, p.Accept) }
+	}
+	status, body, err := fetch(p.URL)
 	if err != nil {
 		return false, "", err
 	}