Update tech_docs/jinja2_framework.md

tech_docs/jinja2_framework.md

@@ -1,3 +1,56 @@
+```plaintext
+Meta-reflection #3:  
+“Everything is an object; YAML is king.”
+
+When you elevate both Jinja2 and Go templates to that plane, the rivalry collapses into a single question:
+
+> Whose *objects* end up serialised to YAML, and who gets to **author** that YAML?
+
+──────────────────────────────────────
+1.  Object Surface (what the engine knows)
+──────────────────────────────────────
+• Jinja2  
+  Anything reachable from Python’s object graph: classes, bound methods, closures, even live sockets.  
+  Resulting YAML can contain tags like `!!python/object/apply:path.to.Class`—a potential RCE when PyYAML’s `UnsafeLoader` is used.
+
+• Go templates  
+  Only the concrete Go values you explicitly pass via `Execute(w, data)`.  
+  YAML serialisation is done by `gopkg.in/yaml.v3` or similar, which by default refuses to serialise unexported fields or func values.  
+  You get maps, slices, structs, scalars—no code, no cycles, no surprises.
+
+──────────────────────────────────────
+2.  Authoring Locus (who writes the YAML)
+──────────────────────────────────────
+Scenario A: YAML is **input**  
+   – Ansible playbooks, Helm `values.yaml`, K8s CRDs.  
+   – Jinja2 is the *consumer*: it ingests YAML → turns it into Python dicts/lists/objects → renders templates.  
+   – Go templates rarely ingest raw YAML; they ingest the Go structs that *represent* the YAML.
+
+Scenario B: YAML is **output**  
+   – Generating Kubernetes manifests, CloudFormation, GitHub Actions.  
+   – Jinja2 can emit YAML via `|to_yaml`, but you must trust the user to disable unsafe tags.  
+   – Go templates emit YAML via `yaml.Marshal`; the Go type system guarantees you cannot serialise a channel or a mutex.
+
+──────────────────────────────────────
+3.  Meta-Axiom Explosion
+──────────────────────────────────────
+If *everything is an object* and *YAML is king*, then:
+
+• The template engine’s job is to decide **which slice of the object graph becomes YAML**.  
+  – Jinja2: “Expose the whole graph, let YAML pick what it can serialise.”  
+  – Go templates: “Expose only the slice you explicitly wired; the rest literally cannot leak.”
+
+• Consequently the *king* (YAML) rules differently in each kingdom:  
+  – Under Jinja2, YAML must defend the castle (with `SafeLoader`, `Representer` overrides).  
+  – Under Go templates, the castle is empty except for the objects you already vetted.
+
+──────────────────────────────────────
+4.  One-Sentence Meta-Moral
+──────────────────────────────────────
+Jinja2 gives YAML a throne in an open courtyard; Go templates build a bunker and let YAML reign only inside it.
+```
+---
+
 What we are really looking at is two different answers to the same meta-question:
 
 > “How much of the host language’s power do we allow to leak into a string that is *mostly* meant to be static markup?”