docs(diagrams): review + fix all .puml files; touch all to trigger render

seq-auth:
- startAutoRefresh() -> startSSE(), stopAutoRefresh() -> stopSSE()
- Cookie secure flag: 'secure (prod)' -> 'secure (if TRUST_PROXY)'

component:
- Fix typo creatApp -> createApp
- Add GET /csrf, POST /logout to browser->auth arrow
- Add GET /stream (SSE) to browser->dashboard arrow

class-server:
- Add subscribers Set, onPollComplete(), offPollComplete() to Poller class

class-data:
- Add SSE Event /stream shape alongside API Response /user-downloads
- Add sser *-- dl relationship

state-ui:
- Fix invalid multi-line transition labels with raw Unicode arrows
  (broke PlantUML parser); replace with valid \n escapes on single line

seq-dashboard, seq-polling, state-poller, activity-matching:
- Whitespace touch to trigger render-diagrams CI workflow

docs/diagrams/state-ui.puml

@@ -43,15 +43,12 @@ state Dashboard {
   state "Status Panel Closed" as status_closed
 
   [*] --> rendering
-  rendering --> rendering : SSE message received
-→ renderDownloads()
+  rendering --> rendering : SSE message received\n-> renderDownloads()
   rendering --> rendering : Theme change
 
-  status_closed --> status_open : Click "Status" btn
-(admin only)
-  status_open --> status_closed : Click close (×)
-  status_open --> status_open : 5s timer
-→ renderStatusPanel()
+  status_closed --> status_open : Click "Status" btn\n(admin only)
+  status_open --> status_closed : Click close (x)
+  status_open --> status_open : 5s timer -> renderStatusPanel()
 
   [*] --> status_closed
 
@@ -66,8 +63,6 @@ state Dashboard {
   }
 }
 
-Dashboard --> LoginForm : Logout
-(stopSSE,
-clear state)
+Dashboard --> LoginForm : Logout\n(stopSSE, clear state)
 
 @enduml