refactor(ui): PR #134 review — MetaScreen/ESC chain tightening, D-192 reword

Addresses Tyre's 9 architecture items from the sprint-36 client review.

- decisions/architecture.md (Tyre #1): D-192 now says "deprecate; removal
  tracked in #868" instead of "remove". The branch does not remove the
  version field or guard — that belongs in the coordinated server+client
  PR. The decision text now matches the code on this branch.
- meta_stack.gd (#2): handle_escape() on a screen with
  closable_by_escape=false now consumes the event unconditionally. Was
  returning whatever on_escape() returned, which default-returned false
  and leaked ESC into main.gd's implant/settings chain — opening the
  settings dialog behind the loading screen.
- debug_console.gd (#4): drop the direct KEY_ESCAPE branch in
  _unhandled_input. ESC now falls through to main.gd → MetaStack, which
  finds the console on top of the stack and closes it via the normal
  path. Other keys are still consumed so movement/action can't leak.
- main.gd (#6, #10): extract the ESC priority chain into
  _handle_menu_key() so "MetaStack → implant → settings" is a named
  thing. Add a comment near connect_to_sim explaining that
  GameState.bookmark_catalog survives the Option A scene transition via
  the autoload.
- main_menu.gd (#7): header comment documenting the double LoadingScreen
  lifecycle — safe today because main_menu.tscn and main.tscn never
  co-exist, noted for future promotion to autoload if that changes.
- meta_screen.gd (#8): apply captures_input symmetrically in open()/
  close() — was set in open() only, so a screen changing the flag
  between open+close kept the opened value forever.
- meta_screen.gd (#9): on_escape() docstring clarifies the tri-state
  (consume-and-hold / consume-and-close / ignore) — and that
  closable_by_escape=false is the screen-wide way to say
  "consume-and-hold".
- bug_report_dialog.gd (#11): capture_cancelled now emits from
  on_close() (covers any close path — ESC, MetaStack pop, programmatic
  close) rather than only on_escape(). A new _completed flag
  distinguishes completion from cancel so the two signals stay
  mutually exclusive.

client/ui/meta/meta_screen.gd

@@ -22,8 +22,7 @@ func open() -> void:
 		return
 	_phase = Phase.OPENING
 	visible = true
-	if captures_input:
-		mouse_filter = Control.MOUSE_FILTER_STOP
+	mouse_filter = Control.MOUSE_FILTER_STOP if captures_input else Control.MOUSE_FILTER_IGNORE
 	on_open()
 	_phase = Phase.OPEN
 
@@ -34,6 +33,7 @@ func close() -> void:
 	_phase = Phase.CLOSING
 	on_close()
 	visible = false
+	mouse_filter = Control.MOUSE_FILTER_IGNORE
 	_phase = Phase.HIDDEN
 	closed.emit()
 
@@ -43,7 +43,16 @@ func is_open() -> bool:
 
 
 ## Called by MetaStack when ESC is pressed with this screen on top.
-## Return true to consume the event (prevent stack pop); false to allow pop.
+##
+## Return true: consumed-and-held — keep this screen open (e.g. "are you sure"
+## prompt was shown, do not close the underlying screen).
+## Return false: did nothing internally — let MetaStack close this screen.
+##
+## To express "consume-and-hold" — the screen must remain open and ESC must NOT
+## fall through to gameplay/implant — set `closable_by_escape = false` instead.
+## MetaStack treats that as: call on_escape (to let the screen react), do not
+## pop, return true so the event stops here. Returning true from `on_escape` is
+## the per-event variant; setting the flag is the screen-wide variant.
 func on_escape() -> bool:
 	escape_pressed.emit()
 	return false

client/ui/meta/meta_stack.gd

@@ -38,12 +38,18 @@ func is_active() -> bool:
 
 ## Handle ESC key. Call from main.gd before HudGroups ESC handling.
 ## Returns true if the event was consumed (callers must return after).
+##
+## A screen on the stack always consumes the event. `closable_by_escape = false`
+## means "I refuse to close on ESC" — not "pass the event through to the
+## implant/gameplay layer." Otherwise an un-escapable screen (e.g. LoadingScreen)
+## would leak ESC to main.gd and open the settings dialog behind it.
 func handle_escape() -> bool:
 	var t = top()
 	if t == null:
 		return false
 	if not t.closable_by_escape:
-		return t.on_escape()
+		t.on_escape()
+		return true
 	if t.on_escape():
 		return true
 	t.close()

client/ui/meta/screens/bug_report/bug_report_dialog.gd

@@ -37,6 +37,7 @@ const RING_SIZE := 60
 
 var _line_edit: LineEdit = null
 var _captured_screenshot: Image = null
+var _completed: bool = false  # set by _on_text_submitted; suppresses on_close cancel
 
 # #507: Pre-allocated ring buffers (no per-tick allocation after _ready).
 # Input ring: replay-format PlayerInput arrays, one per tick.
@@ -210,6 +211,7 @@ func _get_filled_snapshot_count() -> int:
 func start_capture() -> void:
 	if is_open():
 		return
+	_completed = false  # reset completion flag for this capture session
 	# Capture screenshot BEFORE showing the dialog overlay
 	_captured_screenshot = get_viewport().get_texture().get_image()
 	MetaStack.push(self)
@@ -236,17 +238,24 @@ func on_close() -> void:
 		_line_edit.queue_free()
 		_line_edit = null
 	_captured_screenshot = null
+	# Any close path that did not complete is a cancel — covers ESC, MetaStack
+	# pop, programmatic close(). _completed flips to true in _on_text_submitted
+	# right before capture_completed fires, so the two signals stay exclusive.
+	if not _completed:
+		capture_cancelled.emit()
+	_completed = false
 
 
 func on_escape() -> bool:
-	capture_cancelled.emit()
+	# on_close() will emit capture_cancelled — don't double-emit here.
 	return false  # let MetaStack close
 
 
 func _on_text_submitted(text: String) -> void:
 	_save_report(text)
-	close()
+	_completed = true
 	capture_completed.emit()
+	close()
 
 
 func _save_report(description: String) -> void:

client/ui/meta/screens/debug_console/debug_console.gd

@@ -108,10 +108,11 @@ func _unhandled_input(event: InputEvent) -> void:
 		_toggle()
 		return
 	if is_open():
-		# Consume all keyboard events — prevent movement/action leaking through
-		get_viewport().set_input_as_handled()
-		if event.keycode == KEY_ESCAPE:
-			close()
+		# Consume keyboard events so movement/action don't leak to main.gd,
+		# but let ESC fall through to OPEN_MENU → MetaStack.handle_escape().
+		# MetaStack finds this console at the top of the stack and closes it.
+		if event.keycode != KEY_ESCAPE:
+			get_viewport().set_input_as_handled()
 
 
 func _on_input_key(event: InputEvent) -> void:

client/ui/meta/screens/main_menu/main_menu.gd

@@ -3,6 +3,13 @@ extends MetaScreen
 ## New Game: opens character creation screen, then starts game.
 ## Continue: loads most recent save directory.
 ## Load Game: shows sorted save list for manual selection (#257).
+##
+## LoadingScreen lifecycle: this scene instantiates its own LoadingScreen child
+## (see `_ensure_loading_screen`). main.tscn has a separate `$MetaLayer/LoadingScreen`.
+## Safe today because main_menu.tscn and main.tscn never co-exist — the scene
+## transition in `_start_game` replaces the tree wholesale. If that invariant
+## ever changes (e.g. embedding the menu as an overlay), promote LoadingScreen
+## to an autoload to enforce single-instance across the MetaStack.
 
 const GAME_SCENE := "res://scenes/main.tscn"
 const CHARACTER_CREATION_SCENE := "res://scenes/character_creation.tscn"