Adapt @uvmplus's PR #1481 (3ecf7479) to the shared symbol lookup and
named-symbol flow resolver on current main. Missing names return not found
with suggestions, and exact matches with no callers stay empty.
Preserve #1512 definition grouping and --file narrowing, #173 qualified
misses, and codegraph_node's intentional fuzzy file lookup. Port the
upstream regression suite and cover the moved shared lookup paths.
Validation on Linux with Node 22: project build, 74 requested tests,
47 related flow tests, and 16 same-fixture CLI/MCP checks pass. Baseline
captured 12 failing tests and 13 failing fixture checks.
Fixes#1473.
Supersedes #1481.
Co-authored-by: Colby McHenry <colbymchenry@users.noreply.github.com>
