Fix keyword and nested array-copy typing

[luisleo526]

Summary

• accept exact Pine v6 array.copy(id=source) receiver binding in analysis and emission, while rejecting missing, duplicate, mixed, and unknown receiver shapes
• type direct temporary method-copy chains such as array.from(...).copy().get(...) in terminal and nonterminal expressions
• use the actual member name for arbitrary-expression array receiver typing, closing a TypeInferer defect that terminal-return analysis could mask
• preserve fail-closed behavior for arbitrary UDF, slice, map, matrix, reference-element, argument-bearing forward, and recursive boundaries

Validation

• focused compile-enabled terminal-array suite: 95/95
• full native pytest: 1,907 collected, exit 0, 2 expected skips
• release selftest: 8 comparator plus 10 verdict cases
• Pyodide/release parity: 277/277 fixtures, 263 accepted plus 14 expected errors
• frozen differentials: historical 666 and current 812 both have zero status, generated-output, and exact-error diffs
• exhaustive N=4 causal matrix: 16/16 cells and 224/224 probes; all-off, exhaustive, adjudicator, and publication gates true; early stop disabled; fingerprint 074c1b72f5e2cdc450bc58fc15a45395e679d4f9a73ee337a47179bbb20b8d78
• fresh forced-no-cache scraper gate: 416/416 accounted, 409 OK plus the same 7 expected non-OK rows, 0 UP / 0 DOWN
• scoreboard unchanged at 354 Excellent / 47 Strong / 4 Moderate / 2 Weak; 410/410 engine tapes and 411/411 generated C++ outputs are byte-identical

Independent adversarial review found and closed one terminal-analyzer masking gap before publication, then returned GO.

No TradingView source, tape, threshold, grader, or strategy-specific behavior changed.