feat(types): Huge + Angle + Percent polish numeric types (#55)

Types phase 5 (polish). A splice-on-demand numeric runtime
(runtime/native/numeric.ludic, built on the inline Math.* trig) behind three
namespaces:

- Huge.* — idle big numbers (normalized mantissa x 10^exponent): from/add/
  sub/mul/neg/cmp/sign/mantissa/exp/str (scientific 1.23e45). Display-scale,
  not lockstep-exact (BigInt/Decimal for exactness).
- Angle.* — auto-wrapping radians: from_degrees/to_degrees/wrap/sin/cos/add/
  diff (shortest signed rotation)/lerp (shortest arc).
- Percent.* — clamped [0,1]: clamp/of/lerp/apply.

Remaining phase-5 items are already covered (duration=Duration.*,
rune=Unicode.*, i64=long) or need a type-checking pass (handle, typed name,
other sized ints) — tracked for later.

Wired: parser splice trigger (g_uses_numeric), emit_call dispatch, reseeded
seed, a self-asserting example (examples/library/numeric.ludic + feat_case),
per-symbol docs + inventory. All suites green incl. golden renders byte-
identical and the bootstrap fixpoint.

NOTE: fixed `const`s lower to raw-int-typed values (emit_call N_CONST), which
breaks fixed comparisons — the runtime uses inline fixed literals instead.

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

docs/language/angle/_section.md

@@ -0,0 +1,7 @@
+---
+id: angle
+title: Angle
+order: 15
+---
+
+An auto-wrapping angle in radians, so you never juggle <code>% TAU</code> by hand. Every <code>Angle.*</code> result is normalized into <code>[-pi, pi)</code>, which makes <code>diff</code> the shortest signed rotation between two headings and <code>lerp</code> turn the short way around. Build from degrees with <code>Angle.from_degrees</code> (read back with <code>to_degrees</code>), take <code>sin</code> / <code>cos</code>, combine with <code>add</code>, and normalize any raw value with <code>wrap</code>. It builds on the deterministic fixed-point <code>Math.*</code> trig, so results are bit-identical on every platform. Arguments are positional; angles are <code>fixed</code> radians. Spliced in only when a program mentions <code>Angle.*</code>.