docs: design context optimizer — Headroom-inspired pre-LLM compression layer

DESIGN: Pre-submission optimization pipeline that sits between hybrid search
retrieval and the LLM gateway. Search indexes (pgvector + OpenSearch) stay
at full fidelity; only the evidence chunks entering the prompt get optimized.

4-STAGE PIPELINE:
1. CacheAligner — move dynamic content (timestamps, UUIDs) to tail,
   stabilize prefix for LLM provider KV cache hits
2. ContentRouter — auto-detect content type (JSON, code, logs, diffs, text)
   via structural heuristics, route to best compressor
3. Compressors — per-type compression:
   - JsonCrusher (70-90%): field variance, boundary items, key preservation
   - LogCompressor (85-95%): reuses M3.7.7 patterns, keeps errors/traces
   - CodeCompressor (40-70%): signature preservation, body stripping
   - DiffCompressor (60-80%): hunk preservation, context dropping
   - TextCompressor (30-50%): token importance scoring
4. CCR Store — cache originals with hash, inject retrieval hint,
   model can fetch full content if needed (lossless)

REUSES EXISTING CODE:
- lesson.rs normalise() for CacheAligner pattern detection
- lesson.rs markers() + is_cascade() for LogCompressor
- symptom_projection.rs stop words for TextCompressor

INTEGRATION POINT:
- After hybrid search retrieval, before PromptBuilder
- Search quality preserved (full text in pgvector + OpenSearch)
- Only LLM input is optimized

Inspired by Headroom (https://docs.headroomlabs.ai)

k8s/infra/databases/opensearch.yaml

@@ -65,8 +65,8 @@ data:
     # Cluster settings
     cluster.name: poimen-memory
     node.name: ${HOSTNAME}
-    cluster.initial_master_nodes: opensearch-0,opensearch-1
-    discovery.seed_hosts: opensearch-0.opensearch.poimen.svc.cluster.local,opensearch-1.opensearch.poimen.svc.cluster.local
+    cluster.initial_master_nodes: opensearch-0
+    discovery.seed_hosts: opensearch-0.opensearch.poimen.svc.cluster.local
     
     # Network
     network.host: 0.0.0.0
@@ -102,7 +102,7 @@ metadata:
     app.kubernetes.io/name: opensearch
 spec:
   serviceName: opensearch
-  replicas: 2
+  replicas: 1
   selector:
     matchLabels:
       app.kubernetes.io/name: opensearch
@@ -133,7 +133,7 @@ spec:
             - name: CLUSTER_NAME
               value: "poimen-memory"
             - name: OPENSEARCH_JAVA_OPTS
-              value: "-Xms512m -Xmx512m"
+              value: "-Xms1g -Xmx1g"
             - name: DISABLE_SECURITY_PLUGIN
               value: "true"
           
@@ -150,11 +150,11 @@ spec:
           # Resource limits
           resources:
             requests:
-              memory: "512Mi"
-              cpu: "250m"
-            limits:
               memory: "1Gi"
               cpu: "500m"
+            limits:
+              memory: "2Gi"
+              cpu: "1000m"
           
           # Liveness probe
           livenessProbe:
@@ -178,8 +178,7 @@ spec:
           
           # Security context
           securityContext:
-            runAsUser: 0
-            runAsNonRoot: false
+            runAsUser: 1000
       
       # Volumes
       volumes:
@@ -280,8 +279,11 @@ data:
     opensearch_dashboards.index: ".opensearch_dashboards"
     
     # Logging
-    logging.dest: stdout
-    logging.level: info
+    logging.appenders.default.type: console
+    logging.appenders.default.layout.type: pattern
+    logging.appenders.default.layout.pattern: "[%date][%level][%logger] %message"
+    logging.root.appenders: [default]
+    logging.root.level: info
 
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