## ADDED Requirements

### Requirement: Knowledge retrieval SHALL support a disabled-by-default Spring AI sidecar
The retrieval system SHALL allow a Spring AI VectorStore retrieval path to be wired as a sidecar without changing the default `lookup_knowledge` runtime path.

#### Scenario: Sidecar disabled by default
- **WHEN** the application starts without explicit sidecar enablement
- **THEN** `lookup_knowledge` SHALL continue using the existing retrieval path
- **AND** Chat and AIOps runtime behavior SHALL not depend on the sidecar

#### Scenario: Sidecar failure does not break main retrieval
- **WHEN** the Spring AI sidecar is enabled but cannot initialize or query successfully
- **THEN** the existing retrieval path SHALL remain usable
- **AND** the failure SHALL be reported as sidecar status rather than as a main retrieval failure

### Requirement: Knowledge retrieval SHALL normalize sidecar results for comparison
The sidecar retrieval path SHALL expose results in a comparable structure aligned with the current retrieval result shape.

#### Scenario: Comparable result metadata
- **WHEN** sidecar retrieval returns candidates
- **THEN** each comparable result SHALL include source or doc id, title when available, breadcrumb when available, category when available, rank, content preview, and the sidecar score label/value

#### Scenario: Score semantics are explicit
- **WHEN** current retrieval and sidecar retrieval scores are compared
- **THEN** the report SHALL label score semantics by path instead of assuming direct numeric equivalence