Feat v0.9.8 conditional routing SDK primitive

Promote workflow branch-rule evaluation to a generic Starlark
routing.evaluate(rules, data) module available to all extensions.
10 operators, first-match-wins, no permission gate. 8 new tests.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,27 @@
 
 All notable changes to Armature are documented here.
 
+## v0.9.8 — Conditional Routing → SDK Primitive
+
+Promotes the workflow branch-rule engine to a generic Starlark SDK
+module available to all extensions — no permission required.
+
+**New Starlark module: `routing`**
+
+- `routing.evaluate(rules, data)` — evaluates an ordered list of
+  condition rules against a data dict; returns the first matching
+  rule's `target` string, or `None` if no rule matches
+- 10 operators: `exists`, `not_exists`, `eq`, `neq`, `gt`, `lt`,
+  `gte`, `lte`, `in`, `contains`
+- First-match-wins semantics
+- Domain-agnostic: uses `target` (not `target_stage`) so any
+  extension can use it for feature flags, content routing, approval
+  logic, etc.
+- Always available — pure computation, no I/O, no permission gate
+
+**Tests:** 8 new unit tests covering all operators, type coercion,
+first-match-wins, empty/missing/bad input
+
 ## v0.9.7 — Full Read/Write Workflow Starlark Module
 
 Extensions with `workflow.access` permission can now start, advance,