[siktec-lab]

Fixes #42, #43, #44, #45:

• Slice.evalSandbox from guest code: memory cap ignored for small values and replaced by a wrong ceiling for large ones #42: Add memory and maxMemoryBytes serde aliases to SandboxEvalOptions::memory_bytes and stop permanently charging freed child JS heap allocations against parent BOA_KV_MEM_BUDGET after child Slice.evalSandbox exits.
• fuelUsed is a constant 10 for while and do...while loops that finish under the budget #43: Track cumulative loop_iterations_executed in boa_engine::vm::RuntimeLimits across IncrementLoopIteration opcodes and charge proportional loop fuel ((loop_iters / 250).max(1)) on Tier-1 completion.
• Egress DLP block is reported as an environment variable capability error (EGRESS_SECRET_LEAK_BLOCKED) #44: Introduce dedicated SandboxViolation::EgressSecretLeakBlocked variant (Egress DLP Violation (EGRESS_SECRET_LEAK_BLOCKED)) instead of reusing EnvAccessDenied.
• Uncaught error text in Slice.evalSandbox repeats the source location #45: Deduplicate error location parentheticals in finish_boa_compartment_execution, avoid injecting an extra leading newline in standalone SLICEBOA{ wrappers so single-line snippets report :1:, and report Uncaught SyntaxError on invalid JSON in Tier-0 JSON.parse.