Extend rust-performance with build optimization depth (size-opt, feature gates, stripping)

[AlexMikhalev]

Parent Epic: #62

What

Deepen the build optimization coverage in rust-performance SKILL.md beyond the current release/release-lto profiles.

Sections to Add

1. Size-Optimized Profiles -- opt-level = "z", panic = "abort", minimal binary builds
2. Symbol Stripping -- strip = "symbols", strip = "debuginfo", when to use each
3. Feature Gates -- Conditional compilation for optional features, reducing binary size
4. no-std Alternatives -- When and how to use no-std crates for minimal binaries
5. Cross-Compilation -- cross tool, target triples, distribution strategies

Source Reference

Section 11 (Build Optimization and Distribution) from RUST_SYSTEM_PROGRAMMING_BEST_PRACTICES.md

Disciplined Engineering Alignment

Phase	Skill	Build Optimization Relevance
Research	disciplined-research	Audit current binary size and build times; identify unnecessary dependencies; profile compilation
Design	disciplined-design	Specify target profiles per distribution (server vs WASM vs CLI); define feature gate strategy
Implementation	disciplined-implementation	Add profiles incrementally; each profile/feature gate = one step with size measurement
Verification	disciplined-verification	Verify all feature combinations compile; test stripped binaries; compare sizes before/after
Validation	disciplined-validation	Validate binaries work on target platforms; confirm WASM bundle size meets requirements

The SKILL.md should note:

• During design: document profile selection rationale per deployment target
• During verification: include binary size in benchmark report format

Acceptance Criteria

• Build Profiles section extended with size-opt and cross-compilation examples
• Feature gate patterns documented with examples
• Cargo.toml profile examples updated
• Disciplined workflow integration notes included