Swap puppet compiler ENC to the encapic Go binary (#277)

## Why

The puppet-on-k8s compilers classify nodes with a uv/python ENC script (`encapi-enc`). Each fresh compiler pod resolves the script's python dependencies on first invocation, and that resolution fails on cold pods (observed exits 135/2), breaking puppet agent catalog compilation. `encapic` (git.unkin.net/unkin/encapic) is a stdlib-only Go replacement with no runtime dependency resolution — a behavioural drop-in whose output matches the python script byte-for-byte.

## Changes

- Points the compiler `external_nodes` at `/opt/bin/encapic`.
- Reworks the `setup-shared-bins` init container to `curl` the encapic `v0.1.0` `encapic_linux_amd64` release binary (sha256-verified against the published `.sha256`, installed mode 0755) into the shared bins dir, instead of copying the python script and installing uv.
- Removes the `puppet-encapi-enc` configmap generator, its volume and mount, and the `resources/encapi-enc` script. uv was consumed solely by that script (grep of `apps/base/puppet` confirms no other consumer), so its installation is removed too.

`kubectl kustomize apps/overlays/au-syd1/puppet` builds clean.

## Merge gate

Do not merge until the encapic `v0.1.0` release assets exist:
`https://git.unkin.net/unkin/encapic/releases/download/v0.1.0/encapic_linux_amd64` (+ `.sha256`). The init container pulls them at pod start.

## Rollback

Revert this PR to restore the `encapi-enc` configmap script + uv install and repoint `external_nodes`.

---------

Co-authored-by: benvin <neotheo@gmail.com>
Reviewed-on: #277
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

apps/base/puppet/resources/compiler/puppet.conf

@@ -11,7 +11,7 @@ logdir = /var/log/puppetlabs/puppetserver
 rundir = /var/run/puppetlabs/puppetserver
 pidfile = /var/run/puppetlabs/puppetserver/puppetserver.pid
 node_terminus = exec
-external_nodes = /opt/bin/encapi-enc
+external_nodes = /opt/bin/encapic
 autosign = /etc/puppetlabs/puppet/autosign.conf
 storeconfigs = true
 storeconfigs_backend = puppetdb

apps/base/puppet/resources/encapi-enc

@@ -1,55 +0,0 @@
-#!/usr/bin/env -S /opt/bin/uv run --quiet --cache-dir /opt/bin/.cache/uv --script
-# /// script
-# requires-python = ">=3.11"
-# dependencies = ['pyyaml','requests']
-# ///
-"""
-External Node Classifier (ENC) for Puppet.
-
-If the environment specified in the YAML file is 'testing',
-the environment is not included in the output.
-"""
-
-import os
-import sys
-import yaml
-import requests
-
-# In-cluster encapi service (cobbler-wire-compatible endpoint). Plain HTTP,
-# so no CA bundle is needed. Overridable via ENCAPI_URL.
-ENCAPI_URL = os.environ.get("ENCAPI_URL", "http://encapi.encapi.svc.cluster.local")
-
-def fetch_enc_data(base_url: str, hostname: str) -> str:
-    """
-    Fetches and modifies ENC data from a given URL to ensure classes are in list format.
-    """
-    url = f"{base_url}/cblr/svc/op/puppet/hostname/{hostname}"
-    try:
-        response = requests.get(url)
-        response.raise_for_status()
-    except requests.RequestException as e:
-        sys.exit(f"Request failed: {e}")
-
-    data = yaml.safe_load(response.text)
-    data["parameters"] = data.get("parameters", {})
-
-    # Ensure 'classes' is in the desired list format
-    if "classes" in data:
-        if isinstance(data["classes"], dict):
-            data["parameters"]["enc_role"] = list(data["classes"].keys())
-            data["classes"] = list(data["classes"].keys())
-        else:
-            data["parameters"]["enc_role"] = list(data["classes"])
-            data["classes"] = list(data["classes"])
-
-    if "environment" in data:
-        data["parameters"]["enc_env"] = data["environment"]
-        if data["environment"] == "testing":
-            del data["environment"]
-
-    return yaml.dump(data)
-
-if __name__ == "__main__":
-    if len(sys.argv) != 2:
-        sys.exit(f"Usage: {sys.argv[0]} <hostname>")
-    print(fetch_enc_data(ENCAPI_URL, sys.argv[1]))