[Agying3]

Summary

• add the 已观测(x) expression for querying whether an outer value is still MAYBE
• keep the query pure: it does not resolve unknown values or mutate taint paths
• synchronize IDE keyword tables, completion, syntax cards, tests, docs, and ADR-0011

Semantics

• 已观测(未知) -> FALSE
• 已观测(0) and 已观测(1) -> TRUE
• container checks are shallow by design

Verification

• $env:PYTHONIOENCODING='utf-8'; python tests/run_all.py
• 13 suites passed
• python -m py_compile pypython.py tests/test_v5_observed.py
• git diff --check