feat(compiler, std): Implement Phase 1 (defer statements, Option/Result types, try operator ?)

[DZTic]

What and Why

This PR implements Phase 1 of language enhancements for Rux to bring ergonomic resource cleanup, standard error types, and error propagation matching high-performance languages like Rust:

1. defer Statements (defer ; or defer { ... }):

   • Added defer token, AST node (DeferStmt), parsing, and semantic analysis.
   • Implemented deferStack in AstToHirLowering for LIFO automatic scope cleanup at block exit and upon
     eturn.

2. Standard Option and Result<T, E> Enum Types:

   • Added Option (Some, None) and Result<T, E> (Ok, Err, Success, Error) enums to Packages/Rux/Src/.

3. Error Propagation Operator ? (expr? / TryExpr):

   • Added postfix ? parsing with intelligent disambiguation for ternary expressions (cond ? then : else).
   • Lowered TryExpr to HIR unary operator.

Verification

sh cmake -S . -B Build -G Ninja -DRUX_BUILD_TESTS=ON cmake --build Build --config Release ./Bin/Tests/Unit/rux-tests.exe ./Bin/rux --manifest Rux.toml check ./Format.ps1

Checklist

• Branched from dev and targeting dev
• Release build passes locally
• [x]
  ux check /
  ux test passes from the repository root
• [x]
  ux-tests.exe passes (171/171 unit tests)
• Sources formatted with ./Format.ps1
• Tests added: Defer, Option, Result, Try test suites under Tests/Language/