feat(ITC-WP-0017): establish AgenticDrivesFunctional pattern

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a025c2-407a-7a32-b40a-f37a52f03f62

infospace/agent/retrieval-index.yaml

@@ -1,6 +1,6 @@
 schema: info-tech-canon.retrieval-index.v1
 infospace: canon
-item_count: 70
+item_count: 71
 items:
 - id: assimilation/it-capability-canon
   kind: assimilation
@@ -973,6 +973,37 @@ items:
   - type: uses
     target: model/task
   warnings: []
+- id: practice-pattern/agentic-drives-functional
+  kind: practice-pattern
+  title: AgenticDrivesFunctional
+  canonical_path: patterns/AgenticDrivesFunctional.md
+  source_path: patterns/AgenticDrivesFunctional.md
+  summary: 'Reusable canon PracticePattern: AgenticDrivesFunctional.'
+  owned_concepts:
+  - AgenticDrivesFunctional
+  - AgenticFallback
+  - DemandSignature
+  - FunctionalInterfaceCandidate
+  imports:
+  - model/capability
+  - model/governance
+  - model/observability
+  - model/task
+  - scheme/practice-pattern
+  relationships:
+  - type: conforms_to
+    target: scheme/practice-pattern
+  - type: uses
+    target: model/capability
+  - type: uses
+    target: model/governance
+  - type: uses
+    target: model/observability
+  - type: uses
+    target: model/task
+  - type: related_to
+    target: practice-pattern/interface-deprecation-strangler
+  warnings: []
 - id: practice-pattern/interface-deprecation-strangler
   kind: practice-pattern
   title: InterfaceDeprecationStrangler
@@ -1623,6 +1654,12 @@ items:
     target: model/task
   warnings: []
 common_distinctions:
+- id: agentic-fallback-direct-interface
+  title: Agentic fallback vs direct functional interface
+  summary: Use cross-repository agentic work to interpret novel demand; use an owned
+    API, CLI, or MCP surface when the outcome is stable and recurring.
+  source_artifacts:
+  - practice-pattern/agentic-drives-functional
 - id: interface-deprecation-retirement-removal
   title: Interface deprecation vs retirement vs removal
   summary: Deprecation guides and observes callers, retirement ends legacy behavior