Add call graph fixtures for various languages and scenarios

- Introduced `all-edge-reasons.json` to test edge resolution reasons in .NET.
- Added `all-visibility-levels.json` to validate method visibility levels in .NET.
- Created `dotnet-aspnetcore-minimal.json` for a minimal ASP.NET Core application.
- Included `go-gin-api.json` for a Go Gin API application structure.
- Added `java-spring-boot.json` for the Spring PetClinic application in Java.
- Introduced `legacy-no-schema.json` for legacy application structure without schema.
- Created `node-express-api.json` for an Express.js API application structure.

docs/observability/logging.md

@@ -1,6 +1,6 @@
 # Logging Standards (DOCS-OBS-50-003)
 
-Last updated: 2025-11-25 (Docs Tasks Md.VI)
+Last updated: 2025-12-15
 
 ## Goals
 - Deterministic, structured logs for all services.
@@ -20,6 +20,14 @@ Required fields:
 Optional but recommended:
 - `resource` (subject id/purl/path when safe), `http.method`, `http.status_code`, `duration_ms`, `host`, `pid`, `thread`.
 
+## Offline Kit / air-gap import fields
+When emitting logs for Offline Kit import/activation flows, keep field names stable:
+- Required scope key: `tenant_id`
+- Common keys: `bundle_type`, `bundle_digest`, `bundle_path`, `manifest_version`, `manifest_created_at`
+- Force activation keys: `force_activate`, `force_activate_reason`
+- Outcome keys: `result`, `reason_code`, `reason_message`
+- Quarantine keys: `quarantine_id`, `quarantine_path`
+
 ## Redaction rules
 - Never log Authorization headers, tokens, passwords, private keys, full request/response bodies.
 - Redact to `"[redacted]"` and add `redaction.reason` (`secret|pii|policy`).