feat(ITC-WP-0016): establish PracticePattern language

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

infospace/agent/briefs/practice-pattern-interface-deprecation-strangler.md

@@ -0,0 +1,33 @@
+---
+id: agent-brief/practice-pattern-interface-deprecation-strangler
+artifact_id: practice-pattern/interface-deprecation-strangler
+source_path: patterns/InterfaceDeprecationStrangler.md
+source_kind: practice-pattern
+generated: true
+---
+
+<!-- GENERATED by info_tech_canon; do not edit by hand. -->
+
+# Agent Brief: InterfaceDeprecationStrangler
+
+- Artifact ID: `practice-pattern/interface-deprecation-strangler`
+- Kind: `practice-pattern`
+- Canonical path: `patterns/InterfaceDeprecationStrangler.md`
+- Full source: `patterns/InterfaceDeprecationStrangler.md`
+- Summary: Reusable canon PracticePattern: InterfaceDeprecationStrangler.
+
+## Retrieval Hints
+
+Imports and anchors:
+- `model/devsecops`
+- `model/governance`
+- `model/observability`
+- `scheme/practice-pattern`
+
+## Owned Concepts
+
+- `InterfaceDeprecationStrangler`
+
+## Related Distinctions
+
+- **Interface deprecation vs retirement vs removal**: Deprecation guides and observes callers, retirement ends legacy behavior while retaining a metered tombstone, and removal deletes that tombstone only after the evidence gate passes.

infospace/agent/briefs/scheme-practice-pattern.md

@@ -0,0 +1,32 @@
+---
+id: agent-brief/scheme-practice-pattern
+artifact_id: scheme/practice-pattern
+source_path: patterns/PracticePatternScheme.md
+source_kind: practice-pattern-scheme
+generated: true
+---
+
+<!-- GENERATED by info_tech_canon; do not edit by hand. -->
+
+# Agent Brief: PracticePattern Scheme
+
+- Artifact ID: `scheme/practice-pattern`
+- Kind: `practice-pattern-scheme`
+- Canonical path: `patterns/PracticePatternScheme.md`
+- Full source: `patterns/PracticePatternScheme.md`
+- Summary: Contract for canon PracticePattern artifacts: PracticePattern Scheme.
+
+## Retrieval Hints
+
+Imports and anchors:
+- `kernel/itc-core`
+
+## Owned Concepts
+
+- `PatternLanguage`
+- `PracticePattern`
+- `PracticePattern Scheme`
+
+## Related Distinctions
+
+No common distinction is anchored directly on this artifact.

infospace/agent/global-agent-brief.md

@@ -5,8 +5,8 @@
 This brief summarizes the current canon service surface for agents.
 
 - Infospace slug: `canon`
-- Artifact count: 68
-- Retrieval index items: 68
+- Artifact count: 70
+- Retrieval index items: 70
 - Primary confidence command: `make validate`
 - Refresh generated indexes and views with: `make index`
 - Refresh agent briefs and interface templates with: `make agent-briefs`
@@ -29,6 +29,7 @@ This brief summarizes the current canon service surface for agents.
 
 ## Common Distinctions
 
+- **Interface deprecation vs retirement vs removal**: Deprecation guides and observes callers, retirement ends legacy behavior while retaining a metered tombstone, and removal deletes that tombstone only after the evidence gate passes.
 - **Actor vs Subject vs Principal**: Use actor for the acting entity in a context, subject for the entity a policy evaluates, and principal for the authenticated identity bound to access decisions.
 - **Organization Role vs AccessRole vs CARING role**: Organization roles describe responsibility or position; access roles describe permissions; CARING roles classify access-governance needs and analysis.
 - **Policy vs Control vs Evidence**: Policy states intent or rule, control implements or enforces that rule, and evidence records why the claim should be trusted.

infospace/agent/retrieval-index.json

@@ -1,5 +1,13 @@
 {
   "common_distinctions": [
+    {
+      "id": "interface-deprecation-retirement-removal",
+      "source_artifacts": [
+        "practice-pattern/interface-deprecation-strangler"
+      ],
+      "summary": "Deprecation guides and observes callers, retirement ends legacy behavior while retaining a metered tombstone, and removal deletes that tombstone only after the evidence gate passes.",
+      "title": "Interface deprecation vs retirement vs removal"
+    },
     {
       "id": "actor-subject-principal",
       "source_artifacts": [
@@ -43,7 +51,7 @@
     }
   ],
   "infospace": "canon",
-  "item_count": 68,
+  "item_count": 70,
   "items": [
     {
       "canonical_path": "assimilation/it-capability-canon/ASSIMILATION.md",
@@ -1523,6 +1531,42 @@
       "title": "Intent Scope Purposes Pattern",
       "warnings": []
     },
+    {
+      "canonical_path": "patterns/InterfaceDeprecationStrangler.md",
+      "id": "practice-pattern/interface-deprecation-strangler",
+      "imports": [
+        "model/devsecops",
+        "model/governance",
+        "model/observability",
+        "scheme/practice-pattern"
+      ],
+      "kind": "practice-pattern",
+      "owned_concepts": [
+        "InterfaceDeprecationStrangler"
+      ],
+      "relationships": [
+        {
+          "target": "scheme/practice-pattern",
+          "type": "conforms_to"
+        },
+        {
+          "target": "model/governance",
+          "type": "uses"
+        },
+        {
+          "target": "model/observability",
+          "type": "uses"
+        },
+        {
+          "target": "model/devsecops",
+          "type": "uses"
+        }
+      ],
+      "source_path": "patterns/InterfaceDeprecationStrangler.md",
+      "summary": "Reusable canon PracticePattern: InterfaceDeprecationStrangler.",
+      "title": "InterfaceDeprecationStrangler",
+      "warnings": []
+    },
     {
       "canonical_path": "assimilation/intake-and-assimilation-practice.md",
       "id": "practice/intake-and-assimilation",
@@ -1891,6 +1935,29 @@
       "title": "Consumer Alignment Workplan Template",
       "warnings": []
     },
+    {
+      "canonical_path": "patterns/PracticePatternScheme.md",
+      "id": "scheme/practice-pattern",
+      "imports": [
+        "kernel/itc-core"
+      ],
+      "kind": "practice-pattern-scheme",
+      "owned_concepts": [
+        "PatternLanguage",
+        "PracticePattern",
+        "PracticePattern Scheme"
+      ],
+      "relationships": [
+        {
+          "target": "kernel/itc-core",
+          "type": "conforms_to"
+        }
+      ],
+      "source_path": "patterns/PracticePatternScheme.md",
+      "summary": "Contract for canon PracticePattern artifacts: PracticePattern Scheme.",
+      "title": "PracticePattern Scheme",
+      "warnings": []
+    },
     {
       "canonical_path": "profiles/small-saas/artifacts/control.namespace-per-tenant.yaml",
       "id": "small-saas/control/namespace-per-tenant",

infospace/agent/retrieval-index.md

@@ -4,10 +4,11 @@
 
 Schema: `info-tech-canon.retrieval-index.v1`
 Infospace: `canon`
-Items: **68**
+Items: **70**
 
 ## Common Distinctions
 
+- **Interface deprecation vs retirement vs removal**: Deprecation guides and observes callers, retirement ends legacy behavior while retaining a metered tombstone, and removal deletes that tombstone only after the evidence gate passes. Sources: `practice-pattern/interface-deprecation-strangler`
 - **Actor vs Subject vs Principal**: Use actor for the acting entity in a context, subject for the entity a policy evaluates, and principal for the authenticated identity bound to access decisions. Sources: `model/organization`, `model/access-control`, `standard/caring`
 - **Organization Role vs AccessRole vs CARING role**: Organization roles describe responsibility or position; access roles describe permissions; CARING roles classify access-governance needs and analysis. Sources: `model/organization`, `model/access-control`, `standard/caring`
 - **Policy vs Control vs Evidence**: Policy states intent or rule, control implements or enforces that rule, and evidence records why the claim should be trusted. Sources: `model/governance`, `model/security`, `model/observability`
@@ -455,6 +456,16 @@ Items: **68**
 - Imports and anchors: `model/governance`, `model/task`
 - Owned concepts: `Intent Scope Purposes Pattern`, `IntentScopePurposePattern`
 
+### InterfaceDeprecationStrangler
+
+- ID: `practice-pattern/interface-deprecation-strangler`
+- Kind: `practice-pattern`
+- Canonical path: `patterns/InterfaceDeprecationStrangler.md`
+- Source path: `patterns/InterfaceDeprecationStrangler.md`
+- Summary: Reusable canon PracticePattern: InterfaceDeprecationStrangler.
+- Imports and anchors: `model/devsecops`, `model/governance`, `model/observability`, `scheme/practice-pattern`
+- Owned concepts: `InterfaceDeprecationStrangler`
+
 ### Intake and Assimilation Practice
 
 - ID: `practice/intake-and-assimilation`
@@ -535,6 +546,16 @@ Items: **68**
 - Imports and anchors: `model/purpose-demand-extension`, `model/task`
 - Owned concepts: `Consumer Alignment Workplan Template`
 
+### PracticePattern Scheme
+
+- ID: `scheme/practice-pattern`
+- Kind: `practice-pattern-scheme`
+- Canonical path: `patterns/PracticePatternScheme.md`
+- Source path: `patterns/PracticePatternScheme.md`
+- Summary: Contract for canon PracticePattern artifacts: PracticePattern Scheme.
+- Imports and anchors: `kernel/itc-core`
+- Owned concepts: `PatternLanguage`, `PracticePattern`, `PracticePattern Scheme`
+
 ### Namespace Per Tenant Control
 
 - ID: `small-saas/control/namespace-per-tenant`

infospace/agent/retrieval-index.yaml

@@ -1,6 +1,6 @@
 schema: info-tech-canon.retrieval-index.v1
 infospace: canon
-item_count: 68
+item_count: 70
 items:
 - id: assimilation/it-capability-canon
   kind: assimilation
@@ -973,6 +973,29 @@ items:
   - type: uses
     target: model/task
   warnings: []
+- id: practice-pattern/interface-deprecation-strangler
+  kind: practice-pattern
+  title: InterfaceDeprecationStrangler
+  canonical_path: patterns/InterfaceDeprecationStrangler.md
+  source_path: patterns/InterfaceDeprecationStrangler.md
+  summary: 'Reusable canon PracticePattern: InterfaceDeprecationStrangler.'
+  owned_concepts:
+  - InterfaceDeprecationStrangler
+  imports:
+  - model/devsecops
+  - model/governance
+  - model/observability
+  - scheme/practice-pattern
+  relationships:
+  - type: conforms_to
+    target: scheme/practice-pattern
+  - type: uses
+    target: model/governance
+  - type: uses
+    target: model/observability
+  - type: uses
+    target: model/devsecops
+  warnings: []
 - id: practice/intake-and-assimilation
   kind: practice
   title: Intake and Assimilation Practice
@@ -1210,6 +1233,22 @@ items:
   - type: uses
     target: model/purpose-demand-extension
   warnings: []
+- id: scheme/practice-pattern
+  kind: practice-pattern-scheme
+  title: PracticePattern Scheme
+  canonical_path: patterns/PracticePatternScheme.md
+  source_path: patterns/PracticePatternScheme.md
+  summary: 'Contract for canon PracticePattern artifacts: PracticePattern Scheme.'
+  owned_concepts:
+  - PatternLanguage
+  - PracticePattern
+  - PracticePattern Scheme
+  imports:
+  - kernel/itc-core
+  relationships:
+  - type: conforms_to
+    target: kernel/itc-core
+  warnings: []
 - id: small-saas/control/namespace-per-tenant
   kind: profile-artifact
   title: Namespace Per Tenant Control
@@ -1584,6 +1623,13 @@ items:
     target: model/task
   warnings: []
 common_distinctions:
+- id: interface-deprecation-retirement-removal
+  title: Interface deprecation vs retirement vs removal
+  summary: Deprecation guides and observes callers, retirement ends legacy behavior
+    while retaining a metered tombstone, and removal deletes that tombstone only after
+    the evidence gate passes.
+  source_artifacts:
+  - practice-pattern/interface-deprecation-strangler
 - id: actor-subject-principal
   title: Actor vs Subject vs Principal
   summary: Use actor for the acting entity in a context, subject for the entity a