eso: complete migration — chart 2.6.0, all CRs on v1, 1.35 gate cleared

Phase 3 of the ESO 0.12->2.6 migration (the last k8s-1.35 compat-gate blocker).
Climbed external-secrets 0.16.2 -> 0.17.0 -> ... -> 2.6.0 one minor at a time,
each hop applied + verified (ES sync held at 109 Ready every hop; atomic=true
rollback safety net). Crossed the 0.17 cutoff (v1beta1 serving removed) only
after Phase 2 put all 104 ExternalSecrets + 2 ClusterSecretStores on
external-secrets.io/v1. Result: compat-gate now returns "OK: cluster is safe to
upgrade to 1.35.6" (EXIT 0) — the autonomous version-check chain will take k8s
1.34 -> 1.35 on its next nightly run.

Also fixes the repo-wide stale-lock issue that broke CI pipeline 332: the
terragrunt-generated providers.tf declares gavinbunney/kubectl + telmate/proxmox,
but ~28-39 stacks' committed .terraform.lock.hcl predated that ("Inconsistent
dependency lock file: no version selected"). Reconciled via `tg init -upgrade`
and committed so `terragrunt apply`/CI work cleanly again.

Docs: .claude/CLAUDE.md ESO line corrected (104 ESs, v1, chart 2.6.0); plan doc
marked COMPLETE.

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

stacks/plotting-book/.terraform.lock.hcl

@@ -24,6 +24,14 @@ provider "registry.terraform.io/cloudflare/cloudflare" {
   ]
 }
 
+provider "registry.terraform.io/gavinbunney/kubectl" {
+  version     = "1.19.0"
+  constraints = "~> 1.14"
+  hashes = [
+    "h1:9QkxPjp0x5FZFfJbE+B7hBOoads9gmdfj9aYu5N4Sfc=",
+  ]
+}
+
 provider "registry.terraform.io/goauthentik/authentik" {
   version     = "2024.12.1"
   constraints = "~> 2024.10"
@@ -33,29 +41,16 @@ provider "registry.terraform.io/goauthentik/authentik" {
 }
 
 provider "registry.terraform.io/hashicorp/helm" {
-  version = "3.1.1"
+  version = "3.2.0"
   hashes = [
-    "h1:47CqNwkxctJtL/N/JuEj+8QMg8mRNI/NWeKO5/ydfZU=",
-    "h1:5b2ojWKT0noujHiweCds37ZreRFRQLNaErdJLusJN88=",
-    "zh:1a6d5ce931708aec29d1f3d9e360c2a0c35ba5a54d03eeaff0ce3ca597cd0275",
-    "zh:3411919ba2a5941801e677f0fea08bdd0ae22ba3c9ce3309f55554699e06524a",
-    "zh:81b36138b8f2320dc7f877b50f9e38f4bc614affe68de885d322629dd0d16a29",
-    "zh:95a2a0a497a6082ee06f95b38bd0f0d6924a65722892a856cfd914c0d117f104",
-    "zh:9d3e78c2d1bb46508b972210ad706dd8c8b106f8b206ecf096cd211c54f46990",
-    "zh:a79139abf687387a6efdbbb04289a0a8e7eaca2bd91cdc0ce68ea4f3286c2c34",
-    "zh:aaa8784be125fbd50c48d84d6e171d3fb6ef84a221dbc5165c067ce05faab4c8",
-    "zh:afecd301f469975c9d8f350cc482fe656e082b6ab0f677d1a816c3c615837cc1",
-    "zh:c54c22b18d48ff9053d899d178d9ffef7d9d19785d9bf310a07d648b7aac075b",
-    "zh:db2eefd55aea48e73384a555c72bac3f7d428e24147bedb64e1a039398e5b903",
-    "zh:ee61666a233533fd2be971091cecc01650561f1585783c381b6f6e8a390198a4",
-    "zh:f569b65999264a9416862bca5cd2a6177d94ccb0424f3a4ef424428912b9cb3c",
+    "h1:CTWVDQxyq1cQJR/9RJSkXii/gz5zMjxszSw9LmptDh4=",
   ]
 }
 
 provider "registry.terraform.io/hashicorp/kubernetes" {
-  version = "3.1.0"
+  version = "3.2.0"
   hashes = [
-    "h1:oodIAuFMikXNmEtil5MQgP4dfSctUBYQiGJfjbsF3NY=",
+    "h1:OjMar8kVp0LcDtwgRs877g/K/KPAEDVhFewpE3Tp7l8=",
   ]
 }
 
@@ -79,3 +74,11 @@ provider "registry.terraform.io/hashicorp/vault" {
     "zh:ff35fb1ab6add288f0f368981e56f780b50405accd1937131cba1137999c8d83",
   ]
 }
+
+provider "registry.terraform.io/telmate/proxmox" {
+  version     = "3.0.2-rc07"
+  constraints = "3.0.2-rc07"
+  hashes = [
+    "h1:zp5hpQJQ4t4zROSLqdltVpBO+Riy9VugtfFbpyTw1aM=",
+  ]
+}