feat(stdlib): namespaced standard library (issue #2)

Implement the bulk of the namespaced-stdlib proposal (workshopsoft/ludic#2):
156 namespace methods across Math, Text, List, Ease, Collide, World, Net,
Sys, Save, Mem, extended Screen, Color functions, extended Random, and Time.
All deterministic fixed-point; self-hosting (C-free bootstrap fixpoint holds).

Compiler (selfhost/):
- Math.*: sqrt/sin/cos/tan/atan2/asin/acos (fixed-point runtime prelude —
  bit-by-bit isqrt, 256-entry interpolated sine table, Ross atan2), plus
  hypot/dist/dist2/deg_to_rad/rad_to_deg/posmod/wrap/ping_pong/snapped/
  move_toward/smoothstep/lerp/remap/sign/floor/ceil/round.
- Text.* (complete): upper/lower/trim/repeat/pad, split/join/replace,
  and the libc-backed queries.
- List.* (complete): insert/remove_at/remove/sort plus the earlier ops.
- Ease.* (in/out/in_out/back/bounce) and Collide.* (rects/point_rect/
  circles/rect_circle).
- Phase 3: World/Net/Sys/Save namespaced over the bare builtins (byte-
  identical IR) and Mem.* (bytes/words/copy/fill/peek/poke).
- Screen.* extended (line/circle/fill_circle/triangle/fill_triangle via new
  runtime primitives; sprite/sprite_scaled aliases), Color.* functions,
  Random.* (value/int/sign), Time.* (frame/delta/elapsed/now — new
  game-loop frame counter).
- Fix a lexer bug: fixed-point literals with >4 fractional digits overflowed.

Docs & tooling:
- 129 new per-symbol doc pages; gen.py made data-driven (namespaces
  discovered from the docs, no hardcoded list); new check-impl.py enforces
  that every implemented namespace method / keyword / type / phase has a
  doc page, wired into `x test-tools`. Document the previously-undocumented
  keywords (break/continue/where/entry/new/public + and/or/not tokens).
- LSP: namespaced signature help (ns_method_sig) covering every namespace.

Tests: 12 new self-host/regression tests + a golden render for the drawing
primitives. All suites green (selfhost 21, regression 45, tools 29).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

examples/detach.ludic

@@ -11,7 +11,7 @@
 #   25   @OnDetach(Shield): reads the outgoing amount 5, prints 5 + 20
 #   0    the Shield is gone — nothing matches
 #
-#   ./selfhost/game-build.sh build/ludicc examples/detach.ludic /tmp/detach
+#   bin/x game-build bin/ludicc examples/detach.ludic /tmp/detach
 #   /tmp/detach </dev/null
 program Detach {
   property Tag    { v: int = 0 }

examples/draw_prims.ludic

@@ -0,0 +1,13 @@
+# draw_prims.ludic — exercises the extended Screen.* drawing primitives
+# (line/circle/fill_circle/triangle/fill_triangle) for the golden render suite.
+program DrawPrims {
+  handler DrawWorld phase Render {
+    Screen.clear(0x0d1020)
+    Screen.line(x1: 4, y1: 4, x2: 120, y2: 60, color: 0xFF4040)
+    Screen.circle(x: 200, y: 60, radius: 30, color: 0x40FF40)
+    Screen.fill_circle(x: 80, y: 150, radius: 24, color: 0x4060FF)
+    Screen.triangle(x1: 160, y1: 120, x2: 230, y2: 130, x3: 190, y3: 200, color: 0xFFD040)
+    Screen.fill_triangle(x1: 250, y1: 150, x2: 300, y2: 160, x3: 270, y3: 210, color: 0xFF40FF)
+    Screen.show()
+  }
+}

examples/net_demo.ludic

@@ -14,7 +14,7 @@
 #   5. rt_receive()              — the client reconciles to the authoritative x=5
 #
 # Prints 5 / 999 / 5. Build & run with the Ludic toolchain only:
-#   ./build.sh examples/net_demo.ludic --headless && ./build/net_demo_headless
+#   bin/x app examples/net_demo.ludic --headless && ./build/net_demo_headless
 import "net_rt.ludic"
 
 program NetDemo {

examples/reason.ludic

@@ -9,7 +9,7 @@
 #   503    Enemy A despawned in-world (Despawned): drop its loot, 3 + 500
 #   1009   Enemy B outlived the run; at quit (Quit) it skips loot, 9 + 1000
 #
-#   ./selfhost/game-build.sh build/ludicc examples/reason.ludic /tmp/reason
+#   bin/x game-build bin/ludicc examples/reason.ludic /tmp/reason
 #   /tmp/reason </dev/null
 program Reasons {
   property Health { hp: int = 0 }

examples/rng_demo.ludic

@@ -0,0 +1,13 @@
+# rng_demo.ludic — exercises the Random.* extensions (value/int/sign) with a
+# fixed seed, so the sequence is deterministic for the regression suite.
+program RngDemo {
+  handler Seed phase Start { Random.seed(value: 1) }
+  handler Once phase Update {
+    print(Random.int(100))
+    print(Random.int(100))
+    print(Math.floor(Random.value() * 10.0))
+    print(Random.sign())
+    print(Random.int(0))          # 0 (max <= 0)
+    quit()
+  }
+}

examples/time_demo.ludic

@@ -0,0 +1,11 @@
+program TimeDemo {
+  handler Tick phase Update {
+    let f = Time.frame()
+    print(f)
+    if f >= 3 {
+      print(Math.floor(Time.elapsed() * 100.0))
+      print(Math.floor(Time.delta() * 1000.0))
+      quit()
+    }
+  }
+}