chore: chain rename + bump to v0.16.0 (mirror URLs, fix auto-update)

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

chain.json

@@ -0,0 +1,45 @@
+{
+    "$schema": "https://raw.githubusercontent.com/ScoopInstaller/Scoop/master/schema.json",
+    "version": "0.16.0",
+    "description": "Deterministic workflow engine for AI-assisted data processing in regulated environments.",
+    "homepage": "https://flemming.ai/",
+    "license": "Apache-2.0",
+    "architecture": {
+        "64bit": {
+            "url": "https://releases.chain.flemming.ai/v0.16.0/chain-windows-x86_64.exe#/chain.exe",
+            "hash": "3f03737a259b2784c042474aab86f355c388ac508e693919e656b1c4b0478347"
+        }
+    },
+    "bin": "chain.exe",
+    "post_install": [
+        "Write-Host ''",
+        "Write-Host 'Ch∆In installed. Bootstrap the per-user layout with:'",
+        "Write-Host '  chain bootstrap'",
+        "Write-Host 'then'",
+        "Write-Host '  chain daemon start'",
+        "Write-Host ''"
+    ],
+    "checkver": {
+        "url": "https://git.flemming.ai/fai/chain-private/releases.atom",
+        "regex": "<title>v([\\d.]+)</title>"
+    },
+    "autoupdate": {
+        "architecture": {
+            "64bit": {
+                "url": "https://releases.chain.flemming.ai/v$version/chain-windows-x86_64.exe#/chain.exe",
+                "hash": {
+                    "url": "https://releases.chain.flemming.ai/v$version/chain-windows-x86_64.exe.sha256",
+                    "regex": "^([a-fA-F0-9]{64})"
+                }
+            }
+        }
+    },
+    "notes": [
+        "Ch∆In includes a sandboxed WASM runtime. First launch may",
+        "trigger SmartScreen because the binary is not yet",
+        "Authenticode-signed; this is tracked as the remaining",
+        "Windows half of system-gap S-16. Verify the binary",
+        "manually against its ECDSA signature sidecar:",
+        "  chain admin verify --self"
+    ]
+}