LCORE-1446: Add dynamic filter support to Solr vector IO provider

Adds support for dynamic metadata filtering to the Solr vector IO provider, enabling users to filter
RAG query results by metadata fields at runtime.

NOTE: Dynamic filters from requests are **combined with** the existing static `chunk_filter_query`
configuration (e.g., `"is_chunk:true"`) rather than replacing it. This preserves backward compatibility
and maintains the internal schema filtering needed for chunk window expansion to work correctly.

Both filters are joined with AND logic: fq=(is_chunk:true AND )

This approach avoids breaking changes while enabling flexible metadata filtering for use cases like
filtering by platform, version, document type, etc.

- Upstream PR: ogx-ai/ogx#4471

Author: anik120

README.md

@@ -59,7 +59,7 @@ Manual procedure, assuming an existing PyPI API token available:
 ### Prerequisites
 
 - Python >= 3.12
-- Llama Stack == 0.4.3
+- Llama Stack == 0.6.0
 - pydantic >= 2.10.6
 
 ### Installation

lightspeed_stack_providers/providers/remote/solr_vector_io/solr_vector_io/README.md

@@ -8,6 +8,7 @@ A read-only vector_io provider implementation for llama-stack that integrates wi
 - **Vector similarity search** using Solr's KNN query parser
 - **Keyword search** using Solr's text search
 - **Hybrid search** combining vector and keyword search with Solr's native reranking
+- **Dynamic metadata filtering** using OpenAI-compatible filter API (llama-stack 0.6.0+)
 - **Chunk window expansion** for retrieving extended context around matched chunks
 - **Schema-agnostic** field mapping for flexible Solr schema support
 - **OpenAI-compatible API** for vector store operations (read-only methods)
@@ -193,6 +194,139 @@ params = {
 }
 ```
 
+## Dynamic Metadata Filtering
+
+The provider supports dynamic filtering of search results by metadata fields using OpenAI-compatible filter syntax (introduced in llama-stack 0.6.0). Filters are translated to Solr's filter query (`fq`) syntax and combined with the static `chunk_filter_query` from configuration.
+
+### Filter Types
+
+**Comparison Filters:**
+- `eq` - Equal to
+- `ne` - Not equal to  
+- `gt` - Greater than
+- `gte` - Greater than or equal to
+- `lt` - Less than
+- `lte` - Less than or equal to
+- `in` - Value in list
+- `nin` - Value not in list
+
+**Compound Filters:**
+- `and` - All filters must match
+- `or` - Any filter must match
+
+### Usage Examples
+
+**Simple equality filter:**
+
+```python
+from llama_stack_api import ComparisonFilter
+
+response = await adapter.query_chunks(
+    vector_store_id="my-store",
+    query="How to install ansible?",
+    params={
+        "k": 5,
+        "filters": ComparisonFilter(
+            type="eq",
+            key="platform",
+            value="ansible"
+        )
+    }
+)
+# Solr query: fq=(is_chunk:true AND platform:"ansible")
+```
+
+**Range filter:**
+
+```python
+response = await adapter.query_chunks(
+    vector_store_id="my-store",
+    query="Latest features",
+    params={
+        "k": 5,
+        "filters": ComparisonFilter(
+            type="gte",
+            key="version",
+            value=4.0
+        )
+    }
+)
+# Solr query: fq=(is_chunk:true AND version:[4.0 TO *])
+```
+
+**Multiple values with 'in' filter:**
+
+```python
+response = await adapter.query_chunks(
+    vector_store_id="my-store",
+    query="Security best practices",
+    params={
+        "k": 5,
+        "filters": ComparisonFilter(
+            type="in",
+            key="platform",
+            value=["openshift", "kubernetes", "ansible"]
+        )
+    }
+)
+# Solr query: fq=(is_chunk:true AND platform:("openshift" OR "kubernetes" OR "ansible"))
+```
+
+**Compound filters (AND/OR):**
+
+```python
+from llama_stack_api import CompoundFilter, ComparisonFilter
+
+response = await adapter.query_chunks(
+    vector_store_id="my-store",
+    query="Advanced configuration",
+    params={
+        "k": 5,
+        "filters": CompoundFilter(
+            type="and",
+            filters=[
+                ComparisonFilter(type="eq", key="platform", value="openshift"),
+                ComparisonFilter(type="gte", key="version", value=4.12)
+            ]
+        )
+    }
+)
+# Solr query: fq=(is_chunk:true AND (platform:"openshift" AND version:[4.12 TO *]))
+```
+
+**Nested compound filters:**
+
+```python
+response = await adapter.query_chunks(
+    vector_store_id="my-store",
+    query="Troubleshooting guide",
+    params={
+        "k": 5,
+        "filters": CompoundFilter(
+            type="and",
+            filters=[
+                ComparisonFilter(type="eq", key="doc_type", value="guide"),
+                CompoundFilter(
+                    type="or",
+                    filters=[
+                        ComparisonFilter(type="eq", key="platform", value="openshift"),
+                        ComparisonFilter(type="eq", key="platform", value="ansible")
+                    ]
+                )
+            ]
+        )
+    }
+)
+# Solr query: fq=(is_chunk:true AND (doc_type:"guide" AND (platform:"openshift" OR platform:"ansible")))
+```
+
+### Filter Behavior
+
+- **Static filters preserved:** The configured `chunk_filter_query` (e.g., `"is_chunk:true"`) is always applied to maintain proper chunk/parent document separation
+- **Dynamic filters added:** Request filters are combined with static filters using AND logic
+- **String escaping:** Special Solr characters in filter values are automatically escaped
+- **Works with all search types:** Filters apply to vector, keyword, and hybrid search
+
 ## Limitations
 
 This is a **read-only** provider. The following operations are not supported: