refactor(wasi): unify dispatch — single dispatch_core entry point

[avrabe]

Summary

• Merged handlers from dispatch() and dispatch_core_v2() into dispatch_core(), eliminating the three-dispatcher architecture
• Removed dispatch_core_v2(), dispatch_core_via_lift_lower(), complete_allocation(), AllocationRequest, and DispatchResult
• Added missing handlers to dispatch_core(): initial-cwd, error.to-debug-string, resolution, insecure-random-*, sockets
• Removed duplicate unreachable handlers (exit, error resource-drop, get-random-bytes, input-stream drop)
• Net reduction: -144 lines

Test plan

• cargo build -p kilnd — clean
• cargo test -p kiln-wasi --features std — all tests pass
• Component execution verified (hello_rust.wasm)

🤖 Generated with Claude Code

[github-actions]

🔍 Build Diagnostics Report

Summary

Metric	Base Branch	This PR	Change
Errors	0	0	0
Warnings	9	5	-4

🎯 Impact Analysis

Issues in Files You Modified

• 0 new errors introduced by your changes
• 0 new warnings introduced by your changes
• 0 total errors in modified files
• 0 total warnings in modified files
• 0 files you modified

Cascading Issues (Your Changes Breaking Other Files)

• 0 new errors in unchanged files
• 0 new warnings in unchanged files
• 0 unchanged files now affected

Note: "Cascading issues" are errors in files you didn't modify, caused by your changes (e.g., breaking API changes, dependency issues).

✅ No Issues Detected

Perfect! Your changes don't introduce any new errors or warnings, and don't break any existing code.

---

📊 Full diagnostic data available in workflow artifacts

🔧 To reproduce locally:

# Install cargo-kiln
cargo install --path cargo-kiln

# Analyze your changes
cargo-kiln build --output json --filter-severity error
cargo-kiln check --output json --filter-severity warning

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!