feat(stdlib): Perry-native reimplementation of imperative-runtime JIT libs (find-my-way router)

[proggeramlug]

Part of #1677. Blocked by #1681 — do not start until it is merged to main and parity-green.

Problem

find-my-way (Fastify's router) JITs its matcher from routes registered via scattered .on('GET', '/path', handler) calls during app startup. Capturing that at build time means staging the app's init phase — fragile. The realistic answer is a Perry-native equivalent.

Scope

For JIT libraries where the codegen input is assembled by imperative runtime calls and build-time evaluation (Phase 3) is infeasible:

• Ship a Perry-native equivalent behind compilePackages.
• find-my-way radix-tree matcher first — native route registration + lookup, no runtime new Function.

Acceptance criteria

• A Fastify routing sample resolves a representative route table with the native matcher, with no runtime new Function.
• Byte-for-byte parity vs node on route resolution (params, wildcards, constraints as scoped).
• Merged to main, lint clean, parity-green.

Follow-up (after this phase ships)

Re-evaluate whether perry-jsruntime / embedded V8 can be dropped from default builds entirely, using the Phase 0 instrumentation to confirm nothing in the target workloads still routes to it.

[proggeramlug]

Deferring. Phase 4 (Perry-native find-my-way — imperatively-registered runtime routes) is the hardest/lowest-priority class in #1677 and was not started. The self-hosted precompile() mechanism (PR #1814) is the foundation a future revival would build on; route-table registration would need to be made build-time-knowable first. Reopen when prioritized.