AST import edges silently dropped: short ID vs full path ID mismatch #256

Bug

imports_from edges extracted by graphify.extract.extract() are silently dropped during build_from_json() because the import target IDs don't match the file node IDs.

Repro

from graphify.extract import extract
from pathlib import Path

result = extract([
    Path('backend/src/pipeline/steps/summarise-step.ts'),
    Path('backend/src/services/openai/structured-generation.ts'),
])

# Import edge created:
#   source: "backend_src_pipeline_steps_summarise_step_ts"
#   target: "structured_generation_js"     <-- SHORT ID
#
# But the actual file node ID is:
#   "backend_src_services_openai_structured_generation_ts"  <-- FULL PATH ID
#
# Result: edge points to a non-existent node and is silently dropped

Impact

On a 388-file TypeScript codebase, AST extraction found 1443 raw import edges but the final graph had 0 imports_from edges. This makes all cross-file dependencies invisible, causing the graph to fragment into hundreds of disconnected communities that should be connected.

Root cause

extract() creates import target IDs from the import specifier ('./structured-generation.js' → structured_generation_js) without resolving the relative path to the full filesystem path. File node IDs use the full path (backend_src_services_openai_structured_generation_ts).

Expected behavior

Import target IDs should resolve to the actual file node IDs, either:

1. During extraction (resolve ./foo.js relative to the importing file's directory)
2. During build_from_json() (fuzzy match foo_js → *_foo_ts)

Workaround

Post-build script that matches import targets by stem name:

# Strip _js suffix, match stem to file node
stem = "structured_generation"  # from "structured_generation_js"
full_id = file_nodes.get(stem)  # -> "backend_src_services_openai_structured_generation_ts"

This recovered 527 out of 1443 import edges (the rest are external/node_modules).

Environment

• graphifyy 0.4.2
• TypeScript/ESM codebase with .js import extensions
• Windows 11