feat(lang): 0.S - components take states in their header; migrate writes them, never inside a name, never outside the programs given, never into a package's state

- component Name (a: mut A, b: B) { ... }: every getter, default, function and event takes the
  header's states before the instance; a member's call to another passes them on; the glue is
  supplied them; the template never sees them; a read-only one is read-only in every member
- ludic migrate state: a component's members' needs go into its header (added to an existing one,
  mut added where now changed); a field read or a member call inside a component is the compiler's,
  so nothing is written inside a name and no ', )' is left; an entry point that declares states
  already gets the rest after them
- a program's module named like a package gets <Name>AppState; a program's own file its own state;
  a friend module's files go by directory; a package's settable var stays state
- it writes only under the programs and directories given (and runtime/ with --runtime), and
  refuses the whole run naming any other file that would have to change
- a name a package already moved into its state is rewritten through it; a read of the runtime's
  var through the runtime function that answers it (gl_w: gl_width())
- a state's instance supplied by the runtime is not a uses reference
- tests: state/component, rejected/state_component_ro, rendering/ui_render3d, migrate component
  and foreign cases

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

changes/state.md

@@ -25,3 +25,12 @@ Outside the runtime, the drawable's size and scale, the screen's framebuffer and
 size are read and set through its functions (`gl_width()`, `gl_set_drawable(w, h)`,
 `gl_screen_fbo()`, `gl_pixel_scale()`, `rt_map_tile_size()`), and ludic.ui's render3d backend
 installs itself through the `UiRenderers` registry.
+
+A component names the states its members read and change in its header, `component Tally (score:
+mut Score, look: Look) { ... }`: every getter, default, function and event takes them before the
+instance, a member's call to another passes them on, ludic.ui's calls into it are supplied them, and
+the template never sees them. `ludic migrate state` writes those headers (and adds to an entry
+point's or a component's existing list), gives a program's module named like a package a state of
+its own (`FishingAppState`), keeps a package's settable vars as state, rewrites a program's
+references to vars a package already moved into its state, and writes only under the programs and
+directories it is given - a change needed anywhere else stops the run with the files named.