fix: emit strategy.close callsite tokens

[luisleo526]

What changed

• derive a deterministic nonzero strategy.close token from the authored FuncCall line and column
• preserve one token across repeated loop and cloned UDF execution of the same syntactic site
• keep distinct authored close statements independent
• reserve token zero for source-less synthetic nodes and keep strategy.close_all on the compatibility path

Dependency

pineforge-engine #126 is merged at 22fbf5a and its post-merge CI, docs, and code-quality runs are all green. The merged engine now provides the required six-argument overload while preserving the five-argument compatibility path.

Evidence

• deterministic direct, loop, shared-UDF, and source-less token tests pass
• tokens are byte-identical under PYTHONHASHSEED 1 and 987654
• focused strategy.close suite passes
• full current ABI-backed pytest: 2183 passed, 2 skipped
• broader campaign ABI and optional-corpus run: 2422 passed, 16 skipped
• generated C++ compiles against the candidate and now-merged engine; the old engine rejects the sixth argument as expected
• exhaustive 2^2 engine plus codegen matrix passed all 4 cells without early stop
• full validation board completed 416 of 416 with 355 Excellent, 46 Strong, 4 Moderate, 2 Weak, and 0 downgrades

This is the codegen half of a tier-neutral runtime-correctness milestone; it does not claim a score movement.