rig major updates

rig/docs/notes/selftest.md

@@ -18,7 +18,7 @@ rig assumes no configuration. A profile is an overlay on built-in defaults, so a
 
 ## the ports.sh active contract
 
-`ports.sh active` is read POSITIONALLY by two other files: the Makefile takes `$(word 2)` and `$(word 5)`, the Tiltfile takes `_facts[0]..[6]`. Insert a field in the middle and nothing errors: Tilt simply guards on the wrong context or binds the wrong port. The field count and order are the contract, so they are pinned here rather than left to whoever edits `ports.sh` next.
+`ports.sh active` is read POSITIONALLY by two other files: the Makefile takes `$(word 2)` and `$(word 5)`, the Tiltfile takes `_facts[0]..[7]`. Insert a field in the middle and nothing errors: Tilt simply guards on the wrong context or binds the wrong port. The field count and order are the contract, so they are pinned here rather than left to whoever edits `ports.sh` next. The two paths are absolute or `-`, never empty: an empty field would shift the ones after it just the same.
 
 ## the caller's env beats the files
 
@@ -44,7 +44,21 @@ Not a change-detector. The block is derived, never stored, so if the derivation
 
 rig sits inside a host project's tree but must be copyable straight out of it: no imports, no paths, no assumption the host is there. This grep is the whole test of that claim, and until it was added it lived only in prose and in whoever remembered to run it.
 
-The pattern is assembled from fragments so the file does not match ITSELF. Writing it literally would fail forever; excluding the file instead would put a blind spot in the one check that guards the boundary.
+The pattern is assembled from fragments so the file does not match ITSELF. Writing it literally would fail forever; excluding the file instead would put a blind spot in the one check that guards the boundary. It includes the host project's word for a backing service, which rig's workload addons carried until they left, and skips `local/`, where overlays live and may say anything.
+
+## scratch copies
+
+Every check that changes something does it in a copy made by `copy_rig`: without `local/` (overlays, possibly someone else's, possibly large) and `def/`, and without this machine's `PROFILE`, `OVERLAY`, `CLUSTER` and `MANIFESTS_DIR` choices, so a check sets exactly what it tests.
+
+## what runs is an overlay; rig only reads it
+
+The overlay decisions (docs/notes/overlay.md), each against a throwaway overlay in a scratch copy: with nothing named, the same cluster, ports, addons, node count and kind config as before overlays existed; `rig.env` between the profile and `ctrl/.env`, the caller above all; identity from the overlay's folder; its paths relative to itself; a named overlay that does not exist, or a `rig.env` that tries to choose the profile or the overlay, is an error; an overlay's addon found before rig's own and run from rig's `ctrl/`; `persist` refusing; `make -n tilt OVERLAY=...` asking for the overlay's context (make before 4.4 would not pass it to `$(shell)`).
+
+And the two that make an overlay safe to hold someone else's work: rig writes nothing into it (a checksum of the folder before and after `active`, `addons list`, a kind render, `standalone write` and `export`), and nothing from it — neither a value nor its path — reaches a committed kit.
+
+## withdrawn stays withdrawn
+
+One check per entry in STALE.md, each asserting that the withdrawn thing has not come back. The reasoning stays in STALE.md; the check is what makes it more than prose.
 
 ## the Tiltfile hardcodes nothing
 
@@ -62,6 +76,16 @@ Each kit's Makefile exists so nothing wrapping these scripts has to GUESS how to
 
 An export is "take the setup I have here somewhere else", so it carries this machine's CHOICES (profile, ports, manifest dir) and never its credentials: `ctrl/.env` can hold registry and mirror logins next to those choices. The committed per-profile kits carry neither, since they must be the same on any machine. Proven with sentinel values in a scratch copy, because the real `ctrl/.env` may have those keys empty, and an empty value proves nothing.
 
-## optional: Tiltfile evaluates
+## the dev loop parses — tilt and kubectl, no cluster
+
+Parsing the Tiltfile for real is the only way to know it still evaluates. Tilt snapshots a kubectl context first, but it never contacts the cluster while evaluating: given a throwaway kubeconfig whose entries are kind-named (Tilt only runs `local()` freely for contexts it recognises as local) and a `kubectl` that swallows `apply`, `tilt alpha tiltfile-result` evaluates rig's Tiltfile with the starter overlay included, and reports the resources it would deploy.
+
+It runs as `rig`, as a copy under another name — the case that used to stop at load (✖ S4) — and with the data overlay, whose namespace is used but not declared. Skipped, not failed, without tilt or kubectl.
+
+## rig's addons apply verified files, never URLs
+
+The offline example profile must install rig's addons with no network. Each addon therefore asks `deps.sh manifest <NAME>` for a pinned manifest, verified on disk, instead of applying a URL; the check fails if a URL comes back or a manifest is asked for without a pinned sum (versions.md). Their container images still need preloading, and nothing here pretends otherwise.
+
+## the examples are overlays that work as shipped
 
-Parsing the Tiltfile for real is the only way to know it still evaluates, but Tilt snapshots a kubectl context before parsing, so it cannot run without a cluster. Skipped rather than failed when there is none, the same way docgen skips its graphgen section.
+`examples/` is what real overlays are copied from, so every addon there must parse, and every DAG must be valid Python. What they deploy is exercised by the parse checks above, not here.