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/huge/_section.md

@@ -0,0 +1,7 @@
+---
+id: huge
+title: Huge
+order: 14
+---
+
+Idle/incremental big numbers — magnitudes far past what a 32- or 64-bit integer can hold, for prestige currencies and exponential growth. A <code>Huge</code> is a normalized mantissa (a Q16.16 <code>fixed</code> in [1, 10)) times <code>10^exponent</code>, so it can represent 10^100 or 10^1000 while staying one small value. It is a <strong>display-scale</strong> number (about four significant digits), <em>not</em> a lockstep-exact one — keep it out of the deterministic simulation and reach for <code>BigInt</code> / <code>Decimal</code> when exactness matters. Build one with <code>Huge.from</code>, combine with <code>add</code> / <code>sub</code> / <code>mul</code> / <code>neg</code>, compare with <code>cmp</code> / <code>sign</code>, read <code>mantissa</code> / <code>exp</code>, and render as <code>1.23e45</code> with <code>str</code>. Arguments are positional. Spliced in only when a program mentions <code>Huge.*</code>.