Tests: Significantly improved coverage of the unit tests

features/session_cli_uncovered_branches.feature

@@ -0,0 +1,56 @@
+Feature: Session CLI uncovered branches
+  As a developer
+  I want full branch coverage for session CLI commands
+  So that edge cases are tested
+
+  Scenario: session cli branch - _get_session_service constructs service when _service is None
+    Given session cli branch the module-level _service is None
+    When session cli branch I call _get_session_service with mocked container
+    Then session cli branch a PersistentSessionService is returned
+
+  Scenario: session cli branch - _reset_session_service sets _service to None
+    Given session cli branch the module-level _service holds a mock
+    When session cli branch I call _reset_session_service
+    Then session cli branch the module-level _service is None again
+
+  Scenario: session cli branch - create command catches SessionNotFoundError
+    Given session cli branch a mock session service that raises SessionNotFoundError on create
+    When session cli branch I invoke the create command
+    Then session cli branch the exit code is 1
+    And session cli branch the output contains "Error:"
+
+  Scenario: session cli branch - show command with no messages
+    Given session cli branch a mock session service returning a session with no messages
+    When session cli branch I invoke the show command for that session
+    Then session cli branch the exit code is 0
+    And session cli branch the output contains "Session Details"
+    And session cli branch the output does not contain "Recent Messages"
+
+  Scenario: session cli branch - show command with linked plan ids
+    Given session cli branch a mock session service returning a session with linked plans
+    When session cli branch I invoke the show command for the linked-plans session
+    Then session cli branch the exit code is 0
+    And session cli branch the output contains "Linked Plans"
+
+  Scenario: session cli branch - show command with long message content truncated
+    Given session cli branch a mock session service returning a session with a long message
+    When session cli branch I invoke the show command for the long-message session
+    Then session cli branch the exit code is 0
+    And session cli branch the output contains "Recent Messages"
+
+  Scenario: session cli branch - delete command aborted via confirmation prompt
+    Given session cli branch a mock session service for delete
+    When session cli branch I invoke the delete command without --yes and answer no
+    Then session cli branch the delete is aborted
+
+  Scenario: session cli branch - export command catches SessionExportError
+    Given session cli branch a mock session service that raises SessionExportError on export
+    When session cli branch I invoke the export command
+    Then session cli branch the export exit code is 1
+    And session cli branch the export output contains "Export error:"
+
+  Scenario: session cli branch - tell command with stream=True
+    Given session cli branch a mock session service for tell
+    When session cli branch I invoke the tell command with --stream
+    Then session cli branch the exit code is 0
+    And session cli branch the streamed output contains the assistant response