docs: add paper citations, fix pedagogical issues, improve SKILL.md

- Cite arxiv 2602.23922 (Invariant-Driven Automated Testing) in all major docs
- Add Progressive Complexity section to SKILL.md for LLM guidance
- Fix SKILL.md Fast Start example to use deterministic ID generation
- Fix getting-started.md failure output inconsistency
- Fix auth-patterns.md TypeScript syntax in JS doc
- Fix fastify-structure.md Date.now() in test helper
- Fix observe.md misleading workspace heading
- Build: clean | Tests: 849 pass, 0 fail

docs/observe.md

@@ -2,6 +2,8 @@
 
 Runtime visibility and drift detection without blocking by default.
 
+Observe extends the invariant framework from [Invariant-Driven Automated Testing](https://arxiv.org/abs/2602.23922) (Malhado Ribeiro, 2021) to production environments: contracts run continuously against live traffic to detect behavioral drift without affecting requests.
+
 ## What Observe Does
 
 `apophis observe` validates your runtime observe configuration:
@@ -153,9 +155,9 @@ observe: {
 }
 ```
 
-## Workspace Support
+## Monorepo Validation
 
-For monorepos, use `apophis doctor --workspace` to validate observe configuration across all workspace packages.
+For monorepos, use `apophis doctor --workspace` to validate observe configuration across all workspace packages. `observe` itself does not support `--workspace`; use `doctor` to check config in each package.
 
 ## Mode Mismatch