fix(workflow): tell a node the OUTPUTs its edges read - #2670

Verdict: PASS at 6c9eca5
Written-by: Reviewer
Attestation: 6c9eca5 role=Reviewer

Ran at this tip:

$ cd plugins/workflow && node --import ./test/resolve.mjs --test "test/*.test.js"
# tests 475  # pass 475  # fail 0

$ cd plugins/workflow && cp /data/dsh/bot/workspace/p2670/graph.base.js src/graph.js && node --import ./test/resolve.mjs --test test/step-body.test.js test/graph.test.js
# tests 2  # pass 0  # fail 2   (both files abort: graph.js provides no export named 'edgeOutputs')

$ cd plugins/workflow && node -e "const fs=require('fs');let s=fs.readFileSync('src/graph.js','utf8');const a=s.indexOf('export function edgeOutputs');const b=s.indexOf('\n}',a);fs.writeFileSync('src/graph.js',s.slice(0,a)+'export function edgeOutputs(graph, nodeId) { ensure(graph); return [] }'+s.slice(b))" && node --import ./test/resolve.mjs --test test/step-body.test.js test/graph.test.js
# tests 15  # pass 11  # fail 4

$ cd plugins/workflow && cp /data/dsh/bot/workspace/p2670/graph.tip.js src/graph.js && node --import ./test/resolve.mjs --test "test/*.test.js"
# tests 475  # pass 475  # fail 0

Red first, both ways. Reverting plugins/workflow/src/graph.js to the base blob 3b8d4e8c (new tests kept) makes both affected files red (exit 1, 0 pass / 2 fail; the module has no edgeOutputs). Keeping the export but reverting its behaviour (edgeOutputs → []) reds the four new tests: 11 pass / 4 fail — the node gets no state, the handoff never says OUTPUT state / one of: ready, the declared-port merge and the branch walk fail. Restored at the tip: 475/475 green.

审查要点：

• edgeOutputs(item, nodeId): only from === nodeId and when.output; when.else contributes nothing; values deduped in edge order (ready, blocked); no values for an edge without eq. Covered by test/graph.test.js (['ready','blocked'], else skipped, unknown node → []).
• stepBody uses declared ports ∪ edges' read ports, declared wins (type: text on summary), same-name values merged; test/step-body.test.js asserts ['state','summary','verdict'] with no duplicate and state.values = ['ready'].
• index.js: with values it writes OUTPUT state: <one of: ready>; without values it keeps the single OUTPUT <name>: <value> form. Real graph wf-1cdf6ec5 through createWorkflowService yields When you finish, add one line per output: OUTPUT state: <one of: ready>, OUTPUT issue: <value>, … — triage gets state and the prompt carries ready.
• missingVerdicts and the fail path are untouched (no hunk touches them): a step that prints nothing still fails; it is only told which line to print.
• Scope: exactly 7 files (plugins/workflow/**, docs/subsystems/workflow.md, changelog.d/2669-edge-outputs.fixed.md). No template.js, no define-time validation/rejection, no partial settlement; the only change to an old test file is the import line (edgeOutputs), no assertion is weakened.
• check-runs at this tip: everything terminal and green/skipped except enqueue-guard (no Verifier report names the tip 6c9eca56), which this PASS answers. No hold; agent-pr present; body carries Fixes #2669, Owner: Dev, Reviewer: Reviewer; checkpoint block valid (1019 chars, fields ok, checks.at is the full tip).