diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9ca6a79..4580ac5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,15 @@
 # Changelog
 
+## [0.6.15] - 2026-05-07
+
+### Fixed
+- Knowledge ingest now sends Apollo chunk provenance through `context:` while retaining metadata compatibility, so source file, heading, section path, chunk index, and token count persist with document chunks.
+- Batch embedding now falls back to per-chunk `Legion::LLM.embed` when `embed_batch` is unavailable.
+- Retired corpus files now emit explicit observation entries tagged `retired` instead of using an Apollo-unknown `document_retired` content type.
+- Retrieval and synthesis failures are logged through helper-based exception handling, and synthesis returns `nil` instead of presenting error strings as answers.
+- Monitor-only installs now enable the maintenance actor without requiring `corpus_path`.
+- Quality reports count Apollo query access logs with the `query` action recorded by lex-apollo.
+
 ## [0.6.14] - 2026-05-06
 
 ### Changed
diff --git a/lib/legion/extensions/knowledge/actors/maintenance_runner.rb b/lib/legion/extensions/knowledge/actors/maintenance_runner.rb
index 4c598e2..a6a9f80 100644
--- a/lib/legion/extensions/knowledge/actors/maintenance_runner.rb
+++ b/lib/legion/extensions/knowledge/actors/maintenance_runner.rb
@@ -21,16 +21,20 @@ def time
           end
 
           def enabled? # rubocop:disable Legion/Extension/ActorEnabledSideEffects
-            return false unless corpus_path && !corpus_path.empty?
+            return true if corpus_path && !corpus_path.empty?
 
-            true
+            Runners::Monitor.resolve_monitors.any?
           rescue StandardError => e
             handle_exception(e, level: :warn, operation: 'knowledge.maintenance_runner.enabled')
             false
           end
 
           def args
-            { path: corpus_path }
+            path = corpus_path
+            return { path: path } if path && !path.empty?
+
+            monitors = Runners::Monitor.resolve_monitors
+            monitors.any? ? { path: monitors.first[:path] } : { path: nil }
           end
 
           private
diff --git a/lib/legion/extensions/knowledge/runners/ingest.rb b/lib/legion/extensions/knowledge/runners/ingest.rb
index c4777d8..9c98d68 100644
--- a/lib/legion/extensions/knowledge/runners/ingest.rb
+++ b/lib/legion/extensions/knowledge/runners/ingest.rb
@@ -240,7 +240,7 @@ def build_exists_map(chunks)
           private_class_method :build_exists_map
 
           def llm_embed_available?
-            defined?(Legion::LLM) && Legion::LLM.respond_to?(:embed_batch)
+            defined?(Legion::LLM) && (Legion::LLM.respond_to?(:embed_batch) || Legion::LLM.respond_to?(:embed))
           end
           private_class_method :llm_embed_available?
 
@@ -250,9 +250,19 @@ def paired_without_embed(chunks, exists_map)
           private_class_method :paired_without_embed
 
           def build_embed_map(needs_embed)
-            results = Legion::LLM.embed_batch(needs_embed.map { |c| c[:content] }) # rubocop:disable Legion/HelperMigration/DirectLlm
-            results.each_with_object({}) do |r, h|
-              h[needs_embed[r[:index]][:content_hash]] = r[:vector] unless r[:error]
+            if Legion::LLM.respond_to?(:embed_batch)
+              results = Legion::LLM.embed_batch(needs_embed.map { |c| c[:content] }) # rubocop:disable Legion/HelperMigration/DirectLlm
+              results.each_with_object({}) do |r, h|
+                h[needs_embed[r[:index]][:content_hash]] = r[:vector] unless r[:error]
+              end
+            else
+              needs_embed.each_with_object({}) do |chunk, h|
+                result = Legion::LLM.embed(chunk[:content]) # rubocop:disable Legion/HelperMigration/DirectLlm
+                vector = result.is_a?(Hash) ? result[:vector] : result
+                h[chunk[:content_hash]] = vector if vector.is_a?(Array) && vector.any?
+              rescue StandardError => e
+                log.warn(e.message)
+              end
             end
           rescue StandardError => e
             handle_exception(e, level: :warn, operation: 'knowledge.ingest.build_embed_map')
@@ -328,10 +338,10 @@ def retire_file(file_path:)
             return unless Legion::Apollo.respond_to?(:ingest) && Legion::Apollo.started?
 
             Legion::Apollo.ingest( # rubocop:disable Legion/HelperMigration/DirectKnowledge
-              content:      file_path,
-              content_type: 'document_retired',
+              content:      "Retired document: #{file_path}",
+              content_type: 'observation',
               tags:         [file_path, 'retired', 'document_chunk'].uniq,
-              metadata:     { source_file: file_path, retired: true }
+              context:      { source_file: file_path, retired: true }
             )
           rescue StandardError => e
             handle_exception(e, level: :warn, operation: 'knowledge.ingest.retire_file', file_path: file_path)
diff --git a/lib/legion/extensions/knowledge/runners/maintenance.rb b/lib/legion/extensions/knowledge/runners/maintenance.rb
index 4c8a154..abfbcea 100644
--- a/lib/legion/extensions/knowledge/runners/maintenance.rb
+++ b/lib/legion/extensions/knowledge/runners/maintenance.rb
@@ -296,7 +296,7 @@ def quality_summary
           def query_count
             return 0 unless Helpers::ApolloModels.access_log_available?
 
-            Helpers::ApolloModels.access_log.where(action: 'knowledge_query').count
+            Helpers::ApolloModels.access_log.where(action: 'query').count
           rescue StandardError => e
             handle_exception(e, level: :warn, operation: 'knowledge.maintenance.query_count')
             0
diff --git a/lib/legion/extensions/knowledge/runners/query.rb b/lib/legion/extensions/knowledge/runners/query.rb
index 3df5626..f248a9e 100644
--- a/lib/legion/extensions/knowledge/runners/query.rb
+++ b/lib/legion/extensions/knowledge/runners/query.rb
@@ -181,11 +181,14 @@ def synthesize_answer(question, chunks)
                          "Context:\n#{context_text}\n\nQuestion: #{question}\n\nAnswer:"
                      end
 
-            result = llm_chat(message: prompt, caller: { extension: 'lex-knowledge' })
-            result.is_a?(Hash) ? result[:content] : result
+            result = Legion::LLM.chat( # rubocop:disable Legion/HelperMigration/DirectLlm
+              message: prompt,
+              caller:  { extension: 'lex-knowledge' }
+            )
+            result.is_a?(Hash) ? result[:content] : result.content
           rescue StandardError => e
             handle_exception(e, level: :warn, operation: 'knowledge.query.synthesize_answer')
-            "Error generating answer: #{e.message}"
+            nil
           end
           private_class_method :synthesize_answer
 
diff --git a/lib/legion/extensions/knowledge/version.rb b/lib/legion/extensions/knowledge/version.rb
index 6c55127..e38c2de 100644
--- a/lib/legion/extensions/knowledge/version.rb
+++ b/lib/legion/extensions/knowledge/version.rb
@@ -3,7 +3,7 @@
 module Legion
   module Extensions
     module Knowledge
-      VERSION = '0.6.14'
+      VERSION = '0.6.15'
     end
   end
 end