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>

tools/test-lsp.py

@@ -11,7 +11,8 @@ import subprocess
 import sys
 
 ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
-SERVER = os.path.join(ROOT, "build", "ludic-lsp")
+# the toolchain binaries live in bin/ (built by `x tools`); LUDIC_LSP overrides.
+SERVER = os.environ.get("LUDIC_LSP", os.path.join(ROOT, "bin", "ludic-lsp"))
 
 passed = 0
 failed = 0
@@ -171,9 +172,10 @@ def main():
                                                            "end": {"line": 9999, "character": 0}}})
     check_true("inlay hints name query binding types", any(": Stats" == h["label"] for h in hints))
 
+    # a namespaced call resolves to its underlying bare-builtin signature
     sig = c.request("textDocument/signatureHelp",
-                    {"textDocument": uri, "position": position_of(text, "rng_chance(", 11)})
-    check_true("signature help for a builtin",
+                    {"textDocument": uri, "position": position_of(text, "Random.chance(", 14)})
+    check_true("signature help for a namespaced builtin",
                sig and sig["signatures"][0]["label"].startswith("rng_chance("))
 
     toks = c.request("textDocument/semanticTokens/full", {"textDocument": uri})