Refactor routing core, introduce route collection and route finder to reduce router responsibilities

[armanist]

Routing Refactor (Breaking Change)

Summary

This PR introduces a breaking refactor of the routing system as part of the 3.0.0 stabilization work.

The focus is correctness, explicit behavior, and test coverage — not redesign.

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What changed (high-impact)

• Routing internals refactored to an object-based architecture:
  • Route
  • RouteCollection
  • MatchedRoute
  • RouteBuilder
  • RouteDispatcher
• Route matching now produces a MatchedRoute stored on Request
• Global route helpers (current_*, route_*) now read from MatchedRoute
• Middleware ordering is strictly prepend-based and enforced by tests
• Legacy static routing state and implicit controller resolution were removed
• Extensive unit tests added for routing, helpers, and request integration

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⚠️ Breaking changes to review carefully

Contributors should focus review effort on the following areas:

1. Controller resolution

• Controllers are now instantiated directly from the route handler
• Legacy RouteController-based resolution is no longer used
• Verify namespace / FQCN expectations match real applications

2. RouteBuilder behavior

• Grouping, middleware order, caching, and naming are enforced at build time
• Route name uniqueness is validated during build

3. Request → routing boundary

• MatchedRoute is nullable
• Helpers must safely handle the “no route matched” case
• Dispatcher is never invoked when no route is matched

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What this PR does not do

• ❌ No DSL changes
• ❌ No backward-compatibility shims

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How to review

Suggested review order:

1. RouteBuilder and its unit tests
2. Controller resolution logic in RouteDispatcher
3. Route helper tests (expected runtime behavior)

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This refactor affects core request flow — careful review is appreciated.

Closes #412

[andrey-smaelov]

1. There are several temp files were pushed (probably by accident) need to be removed
2. There are several new error messages that appears all over the code, while need to be placed into ExceptionMessages class