docs: update architecture.md to reflect learn workflow's preventive automation

The learn workflow now evaluates prevention opportunities and creates
DeepSchemas and DeepReview rules. Updated three sections in architecture.md
to document this capability.

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

Author: nhorton

doc/architecture.md

@@ -483,7 +483,7 @@ DeepWork includes a built-in job called `deepwork_jobs` for managing jobs. It pr
 - **`repair`** workflow: `fix_settings` → `fix_jobs` → `errata`
   - Cleans up and migrates DeepWork configurations from prior versions
 - **`learn`** workflow: `learn`
-  - Analyzes conversation history to improve job instructions and capture learnings
+  - Analyzes conversation history to improve job instructions, capture learnings, and create preventive automation (DeepSchemas and DeepReview rules)
 
 These are auto-discovered at runtime by the MCP server from the Python package.
 
@@ -532,7 +532,7 @@ User: /deepwork new_job
 
 ### The `learn` Workflow
 
-Analyzes conversation history to improve job instructions and capture learnings:
+Analyzes conversation history to improve job instructions, capture learnings, and create preventive automation:
 
 ```
 User: /deepwork_jobs.learn
@@ -551,10 +551,14 @@ Claude: I'll analyze this conversation for DeepWork job executions...
         Bespoke learnings captured:
         ✓ Created AGENTS.md with project-specific notes about this competitive research instance
 
+        Prevention opportunities evaluated:
+        ✓ Created DeepSchema for competitor_profiles/ output format
+        ✓ Added DeepReview rule to enforce source prioritization in research steps
+
         Job instructions updated in place. Changes take effect on next workflow run.
 ```
 
-This standalone skill can be run anytime after executing a job to capture learnings and improve instructions.
+This standalone skill can be run anytime after executing a job to capture learnings, improve instructions, and create preventive automation (DeepSchemas and DeepReview rules).
 
 ### Step Instructions at Runtime
 
@@ -742,6 +746,7 @@ The `/deepwork_jobs.define` command:
 The `/deepwork_jobs.learn` command:
 1. Identifies doc spec-related learnings (quality criteria issues, structure changes)
 2. Updates doc spec files with improvements
+3. Evaluates prevention opportunities and creates DeepSchemas and DeepReview rules
 
 See `doc/doc-specs.md` for complete documentation.