fix(docs): Update navigation URLs and improve metrics error handling

Documentation URL Updates:
- Update /systems/overview → /systems throughout reading guide
- Update article and system README navigation links
- Ensures consistent URL structure across documentation

Metrics Service Improvement:
- Gracefully handle missing metrics file (return empty dict)
- Prevents crashes in containers without TIA mount
- Updated docstring to reflect new behavior
- Still raises YAMLError for parsing issues

Impact: More resilient metrics loading, cleaner navigation URLs

Author: Scott Senkeresty

docs/READING_GUIDE.md

@@ -144,7 +144,7 @@ You'll understand SIL's theoretical foundations and research trajectory.
 
 ### Reading Sequence
 
-1. **[Innovation Overview](/systems/overview)** (10 min)
+1. **[Innovation Overview](/systems)** (10 min)
    - Summary of all innovations
    - Impact metrics and adoption
 
@@ -229,15 +229,15 @@ Research contributions and theoretical frameworks.
 
 ### 🛠 Tools
 Documentation for production tools (Reveal, TIA, Beth).
-→ [View tools directory](/systems/overview)
+→ [View tools directory](/systems)
 
 ### 🏗 Architecture
 Technical architecture and system design.
 → [View architecture docs](/architecture/overview)
 
 ### 💡 Innovations
 Innovation portfolio — techniques and tools built.
-→ [View innovations](/systems/overview)
+→ [View innovations](/systems)
 
 ### 👤 Meta
 About the founder, influences, FAQ.
@@ -269,7 +269,7 @@ All 12 SIL projects detailed.
 → [Stewardship Manifesto](/meta/stewardship-manifesto), [Safety Thresholds](/meta/safety-thresholds)
 
 **See what's built**
-→ [Project Index](../projects/project-index), [Innovation Portfolio](/systems/overview)
+→ [Project Index](../projects/project-index), [Innovation Portfolio](/systems)
 
 **Get questions answered**
 → [FAQ](/meta/faq), [Glossary](/foundations/glossary)

docs/articles/README.md

@@ -137,7 +137,7 @@ session_provenance: "[session-id if created in session]"
 ## Related Directories
 
 - [Foundations](/foundations/overview) - Foundational principles and frameworks
-- [Systems](/systems/overview) - Practical usage guides for SIL systems
+- [Systems](/systems) - Practical usage guides for SIL systems
 - [Research](/research/overview) - Academic-style research papers
 
 ---

docs/systems/README.md

@@ -36,7 +36,7 @@ Some tools implement specific SIL innovations:
 
 Some tools are applications (not innovations themselves) that demonstrate SIL principles in production.
 
-**See also:** [Innovations](/systems/overview) for innovation descriptions and the inverse mapping
+**See also:** [Innovations](/systems) for innovation descriptions and the inverse mapping
 
 ---
 
@@ -91,7 +91,7 @@ As SIL projects mature, more production tools will be featured here:
 - **tiacad** - Declarative parametric CAD in YAML - [Production v3.1.2](https://github.com/Semantic-Infrastructure-Lab/tiacad)
 - **genesisgraph** - Verifiable process provenance - [Production v0.3.0](https://github.com/Semantic-Infrastructure-Lab/genesisgraph)
 
-See all **[Innovations →](/systems/overview)**
+See all **[Innovations →](/systems)**
 
 ---
 

src/sil_web/services/metrics.py

@@ -33,17 +33,19 @@ def _load_metrics(self) -> Dict[str, Any]:
         """Load metrics from YAML file.
 
         Returns:
-            Metrics dictionary
+            Metrics dictionary (empty dict if file doesn't exist)
 
         Raises:
-            FileNotFoundError: If metrics file doesn't exist
             yaml.YAMLError: If YAML parsing fails
         """
         if not self.metrics_path.exists():
-            raise FileNotFoundError(
-                f"Metrics file not found: {self.metrics_path}\n"
-                "Expected canonical metrics at: ~/src/tia/metrics/sil-metrics.yaml"
-            )
+            # Gracefully handle missing metrics file (e.g., in containers without TIA mount)
+            # Return empty structure to prevent crashes
+            return {
+                "systems": {},
+                "websites": {},
+                "lab": {},
+            }
 
         with open(self.metrics_path) as f:
             return yaml.safe_load(f)