[phase 3.3] add feature-request issue template

Author: cmangun

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,37 @@
+---
+name: Feature request
+about: Propose new behavior or an enhancement
+title: "[feature] "
+labels: ["enhancement"]
+---
+
+## Problem
+
+What user-visible problem does this solve, or what current behavior is inadequate?
+
+## Proposed change
+
+What should the component do differently? Be concrete about inputs, outputs, and error modes.
+
+## ADR check
+
+Does this change touch any of:
+
+- [ ] Receipt schema, canonicalization, hashing, or signing semantics
+- [ ] Hash-chain or bundle composition rules
+- [ ] Policy-decision-receipt shape, decision semantics, or default posture
+- [ ] Eval-harness scenario taxonomy or regression-gate semantics
+- [ ] Any cross-component interop contract documented in [agentic-evidence/INTEROP.md](https://github.com/cmangun/agentic-evidence/blob/main/INTEROP.md)
+
+If any box is checked, this proposal needs an ADR before it can merge. Link the draft ADR (or open one) in `adrs/NNNN-<slug>.md` per the local `adrs/0000-template.md` structure.
+
+## Compatibility implications
+
+Per [agentic-evidence/VERSIONING.md](https://github.com/cmangun/agentic-evidence/blob/main/VERSIONING.md):
+
+- [ ] Backward compatible (no consumer changes required)
+- [ ] Backward incompatible — breaking change requires VERSIONING.md §2 review and a major-version bump on this component
+
+## Alternatives considered
+
+What did you rule out and why? (Mirrors the ADR template's `## Alternatives Considered` section so the request transitions cleanly into an ADR if accepted.)