fix: preserve edge confidence in call trace results

[cookerpapa]

Preserve confidence in call trace results (point 4 of #330), complementing #335's import-resolution fix.

• Keep the original edge confidence in direct and BFS hits.
• Expose pathConfidence as the weakest grade on the existing first BFS path.
• Include both fields in CLI JSON and show confidence in shared CLI/MCP output.
• Document the semantics; cover all four grades, both directions, cycles, diamonds, multi/file seeds, unresolved endpoints, and a real CLI/MCP fixture.

Traversal order, deduplication, depth, and resolution remain unchanged.

Validation:

• All 7 new regressions pass; the initial 6 fail on main before the fix.
• A targeted run had 153/154 passing tests; the remaining exact-output assertion was updated for the label. The final CLI/confidence run passes all 21 tests; the other 133 passed in the earlier run.
• npm run build and git diff --check passed.

[trailhq-graft]

🌱 graft blast radius

1 area changed → 4 areas can be affected. 8 dependent symbols, depth 2.
Tests: 1 area updated its tests.
Tag: @anirudhkumar-nanonets — 5 of 5 areas · @shhdwi — 4 of 5 areas

flowchart TB
  A0(("Tool Invocation<br/>3 symbols"))
  A1(("Blast Radius<br/>2 symbols"))
  A2(("Workspace Federation<br/>2 symbols"))
  A3(("CLI Entry Point<br/>1 symbol"))
  classDef reached fill:#D9EDF3,stroke:#3AA7C9,stroke-width:1.5px,color:#0E313C;
  class A0,A1,A2,A3 reached;

Loading

Can be affected	Symbols	Nearest hop	Reached from
Tool Invocation	3	src/mcp/tools.ts:L132-L147 renderMatches — calls, depth 1	Call Graph Traversal
Blast Radius	2	src/blast/blast.ts:L179-L269 blastRadius — calls, depth 1	Call Graph Traversal
Workspace Federation	2	src/graph/workspace.ts:L659-L695 federateCallers — calls, depth 1	Call Graph Traversal
CLI Entry Point	1	src/cli.ts:L1-L1197 cli.ts — calls, depth 2	Call Graph Traversal

Who knows this code — 2 people across 5 areas

Area	Who knows it
Call Graph Traversal · changed	@shhdwi — 7 commits, last 2mo ago · @anirudhkumar-nanonets — 5 commits, last 17d ago
Tool Invocation · affected	@shhdwi — 14 commits, last 29d ago · @anirudhkumar-nanonets — 7 commits, last 8d ago
Blast Radius · affected	@anirudhkumar-nanonets — 3 commits, last 14d ago
Workspace Federation · affected	@shhdwi — 6 commits, last 29d ago · @anirudhkumar-nanonets — 3 commits, last 30d ago
CLI Entry Point · affected	@anirudhkumar-nanonets — 36 commits, last 8d ago · @shhdwi — 23 commits, last 28d ago

Ownership is git history over each area's own files, weighted towards recent work (120-day half-life). Merge commits and bots are dropped, and you are dropped from your own PR. A name with no @ has no GitHub handle in its commit email — tag them by hand, or add a .mailmap entry. A suggestion from history, not a CODEOWNERS rule.

All 8 dependent symbols, grouped by area

Tool Invocation — 3 symbols in 1 file

• src/mcp/tools.ts:L132-L147 — renderMatches (calls, depth 1)
  136: hitsFor: (n: NodeV1) => EdgeHit[],
• src/mcp/tools.ts:L153-L199 — callWorkspaceTool (calls, depth 2)
• src/mcp/tools.ts:L247-L329 — callSingleTool (calls, depth 2)
  281: // file at depth>1 it walks the file node AND every symbol defined in

Blast Radius — 2 symbols in 1 file

• src/blast/blast.ts:L179-L269 — blastRadius (calls, depth 1)
  193: /** Merged dependents, keyed by node id, at the shallowest depth any file reached
• src/blast/blast.ts:L388-L396 — blastRadiusIn (calls, depth 2)

Workspace Federation — 2 symbols in 2 files

• src/graph/workspace.ts:L659-L695 — federateCallers (calls, depth 1)
  681: else for (const h of hits) lines.push(hitLine(direction, h, showDepth));
• src/graph/workspace-cli.ts:L132-L144 — runWorkspaceCallers (calls, depth 2)

CLI Entry Point — 1 symbol in 1 file

• src/cli.ts:L1-L1197 — cli.ts (calls, depth 2)
  1: #!/usr/bin/env node

Test signal per changed area — 1 ✓

Reached = a node under a test path has a resolved edge into the changed symbol. It undercounts anything called indirectly — through a CLI, a spawned process or a dynamic import — so read a low ratio as “look here”, never as a coverage gate.

• ✓ Call Graph Traversal — 4 of 6 reached · 1 test file changed here: test/graph-confidence.test.ts
  • not reached: hitJson, weakestConfidence

4 test suites also reference this code

4 symbols, kept out of the diagram and the table so they cannot crowd out the areas a reviewer has to look at.

• test/graph-references.test.ts
• test/graph-traverse.test.ts
• test/regression-single-repo.test.ts
• test/workspace.test.ts

⚠️ 1 changed file not in the graph (README.md) — no parser claims the extension, or the index predates the file.

_{graft blast · origin/main...HEAD · depth 2 · 5 changed files}

Open the interactive graph → — click an area to see its dependent symbols at file:line.