[dajiaohuang]

Resolves #159

Description

Resolve relationship display names to emitted node IDs at the JSON target boundary, before collecting FK flags or formatting edges. This preserves short/custom node names without dangling edge IDs or missing FK column flags, and leaves shared input relationships unchanged.

Validated with public DbtErd(artifacts_dir=..., target="json", entity_name_format="table").get_erd() on entirely authored tiny manifest v12/catalog v1 artifacts: both edge endpoints resolve to emitted nodes, customer_id is flagged, and the JSON schema passes. The regression fails on the base and passes with this change.

Checks: complete unit suite 575 passed (7 existing Click deprecation warnings); changed-file Ruff lint/format and git diff --check pass. Python 3.13 on Windows. No live dbt, database, Cloud API, or downstream editor acceptance testing. CI results are not claimed.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests
• Docs changes are not required for this correction of the documented node-ID contract

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (e7783aa) to head (f60bb6e).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #163      +/-   ##
===========================================
+ Coverage   99.90%   100.00%   +0.09%     
===========================================
  Files          45        45              
  Lines        2163      2166       +3     
===========================================
+ Hits         2161      2166       +5     
+ Misses          2         0       -2     

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[datnguye]

LGTM thanks @dajiaohuang