headplane: point OIDC at the real Authentik app; rotate tailnet keys

The Authentik provider and application now exist (slug "headplane", which
is what makes the issuer .../application/o/headplane/), so the client ID
is a real value rather than a placeholder, and the client secret and
headscale API key are in sops.

The tailscale pre-auth keys for neptun and jupiter are rotated because
the tailnet was recreated from scratch: the old headscale database went
with the VPS's OS disk, so every key issued against it is meaningless to
the new control server.

Note the headscale API key defaults to a 90d expiry. When it lapses
headplane stops listing nodes with no obvious cause -- `headscale apikeys
list` shows the date.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

secrets/jupiter.yaml

@@ -1,6 +1,6 @@
 samba_password: ENC[AES256_GCM,data:K3FtKC0CrOLMyfQokmxxlyUnDPo=,iv:9bTE/S/i05LJYldOHuBuz3+g8JdTuq0ysFFgXOmfti8=,tag:77NIxy7qpHRqCmbOR83AfA==,type:str]
 darman_password: ENC[AES256_GCM,data:DOHHlM4Qdw4WgkN+/M51n2LMjJqq5MS0FeGEH8Pz3297yUZ8jBDOKRS/Tek9stC05JKEQRtn/vVVbAY0nXs20MwrsDMo+IEFXx7Ms90vVyYIYe5O5/0aQkPq84vcwGN0RW1Rj5Y3s38vWA==,iv:DAqHbvOBq7FT7ALbmBXJ0HadEGEsL8V2e7R99H5ZH0s=,tag:9XpiRFIbaZjMn59uHCOA1g==,type:str]
-tailscale_authkey: ENC[AES256_GCM,data:GJjN9zdU3zNBxA8cEBdsmjDrj8G/m04r8JRCEDZkdd7jYplEHyLfhbMcIyZIBe3Sh4d3PM/PcKb191LZoMg/b1G4hiVwciaCoMY0O9kAhRg/aYHXluSIBQ==,iv:R3OsZ+3to0tBhF4IaaSHm0afkw5o0KfXkcTdT9HFucg=,tag:QQNXC9ya88lO087iGIc1sw==,type:str]
+tailscale_authkey: ENC[AES256_GCM,data:LjRXyFW1SbhUiXbCQnRKinJluGfQWsjS7TTP/TMvx2noP6aFNrcYMvitG+OqLAlNEQAy0bcxZejZgJN+yNS+5iuy2F7OXhrpO7Df0JHkyMvQpnaH2XBEsw==,iv:QxVkB6GtZOYWFAOFVdBQMU2Hb/2OwBRCLHdfxoDF/ME=,tag:PBL0TV6yZJSu4+TGpycf/A==,type:str]
 mediamanager_token_secret: ENC[AES256_GCM,data:g75vj1E6B029O076yV3DS/1z99Tq6wMhEVx+ULYDjHsplyA+vqVRvBlviC64V47IMqKd9k2eTGBJ98Ptv3UIjbr446xZinz0c7PZgHU0XOX4EUcB1ORloMFZIv1zUv8VRjUISUQnn/vRk60e7u8eXrOrgXjxfnoBKrdKZmqxhAM=,iv:2t0XBExC9RvbTomezka+99/LtJl64zNwneA7WWc4ju0=,tag:SVCYuw0n6JevnvoQOIkjPw==,type:str]
 sabnzbd_api_key: ENC[AES256_GCM,data:6UW1u2Ikmnq34t4H4k/4C44SJeFHRlaPjWwUjEfH1GQ=,iv:sGsd8Sd2pfUhTUDg6PlRzfVYejRbF69jmDTIa2fvY4M=,tag:3fOLgU1K1gKHxQ3J1+3oRQ==,type:str]
 prowlarr_api_key: ENC[AES256_GCM,data:ab1QACaagI8ACJXFUy8r9X9lgYwRo1byUmhBPSRWwKk=,iv:EcuF6EN/4mWxlXi6R1qDzv4rOw6AT+OGSNQaaBwjJHg=,tag:hixHrbQWU6QQZNMM5rNDsg==,type:str]
@@ -25,7 +25,7 @@ sops:
             CzjSDQZTcseEXZNwuzZcfB5Mvq0BQvjOj7lGuxzuE4qwWkdJWGfVLQ==
             -----END AGE ENCRYPTED FILE-----
           recipient: age1zak7glavmg4026p2389fyqe769vqm4jrryknuqckgqq4merz5f7q44rkkt
-    lastmodified: "2026-07-18T00:02:37Z"
-    mac: ENC[AES256_GCM,data:By7/CkQ8bftrGzXwaD9gl1G/iV5AuJEnxHUAK1wMivzUj4mjTvtd3m/RaDd9aFuplNREKBAvUuH4WJ4RrrK+NTNqEsy+VUxch4n/3QC0TSjiEersJR8GpSbfa+AlZ7xNxS11AvV0NGW0PZzxIToR75Yn+hW4SoqeoLy+Nr3b+3U=,iv:sBdbOZl7JbzcR7kq0cyMxv9RATIzs0SheoC32H38iWA=,tag:XeL54IV5xK8+Oa7JhWPTkw==,type:str]
+    lastmodified: "2026-07-20T07:51:55Z"
+    mac: ENC[AES256_GCM,data:CBQrHpdIOn35CIrZaqZqZd/V4pp+bMNygXJoYwlOvwAtb49ElqmQgSZxWVgTKpTNZpMkqYie6HQB0c4vsmU/BYeLQKJNYBQvBxIrTQr4wMURj2jBMhtVT2osX5cUpNakoHZUdz6ARXyYGEVOBzMY77vSxk6VkVi5CFmeOETkcik=,iv:a6iTeIlR2S65pTrH+juS6kEhpbiaAmhcPLssasUPZ58=,tag:QP+LMclWU9SO5/uPI/Nwwg==,type:str]
     unencrypted_suffix: _unencrypted
     version: 3.13.1