Add SyncPlay stats-for-nerds page, manual sync button, and release pipeline

Phase 0 scaffold plus everything since: quality negotiation, host-relay,
and active drift correction were each built and reverted after real bugs
in live use (see PLAN.md for the full account of each). What remains is
read-only SyncPlay observability (live drift/playback stats page) and a
one-shot manual "sync me to group" action, plus Phase 5 packaging/release
tooling (build.yaml, manifest.json generator, Gitea Actions release
workflow) to distribute it as a proper plugin repository.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

dev/docker-compose.yml

@@ -0,0 +1,18 @@
+services:
+  jellyfin-dev:
+    image: linuxserver/jellyfin:10.11.6
+    container_name: jellyfinsyncplus-dev
+    environment:
+      - PUID=1000
+      - PGID=1000
+      - TZ=Etc/UTC
+    ports:
+      - "8096:8096"
+    volumes:
+      - ./config:/config
+      - ./plugins/JellyfinSyncPlus_0.1.0.0:/config/data/plugins/JellyfinSyncPlus_0.1.0.0
+      # Real video content for testing Phase 2 relay. Read-only: recordings here are
+      # never to be deleted or modified by this project, mounting :ro enforces that
+      # rather than just relying on discipline.
+      - /mnt/geforce:/media/geforce:ro
+    restart: "no"

dev/extract-private-refs.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# Extracts the private (non-NuGet) Jellyfin server assemblies our plugin needs
+# a compile-time reference to -- see PLAN.md "Known friction / risks" for why.
+# Re-run this after the pinned server image (dev/docker-compose.yml) changes.
+set -euo pipefail
+
+CONTAINER=jellyfinsyncplus-dev
+JELLYFIN_VERSION=10.11.6
+DEST="$(dirname "$0")/../lib/jellyfin-${JELLYFIN_VERSION}"
+
+mkdir -p "$DEST"
+docker cp "${CONTAINER}:/usr/lib/jellyfin/bin/Emby.Server.Implementations.dll" "$DEST/"
+docker cp "${CONTAINER}:/usr/lib/jellyfin/bin/Jellyfin.Api.dll" "$DEST/"
+
+echo "Extracted to $DEST"

dev/package-release.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# Builds, packages, and updates manifest.json for a tagged release. Used by
+# .github/workflows/release.yml; safe to run locally too for a dry run.
+#
+# Required env vars:
+#   VERSION      -- e.g. 0.2.0.0 (must match build.yaml's version)
+#   SERVER_URL   -- e.g. https://gitea.mrcynic.site
+#   REPO_OWNER   -- Gitea org/user the repo lives under
+#   REPO_NAME    -- Gitea repo name
+set -euo pipefail
+
+: "${VERSION:?VERSION env var required, e.g. 0.2.0.0}"
+: "${SERVER_URL:?SERVER_URL env var required, e.g. https://gitea.mrcynic.site}"
+: "${REPO_OWNER:?REPO_OWNER env var required}"
+: "${REPO_NAME:?REPO_NAME env var required}"
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT"
+
+echo "Building Release configuration..."
+dotnet build src/JellyfinSyncPlus/JellyfinSyncPlus.csproj -c Release
+
+BUILD_VERSION=$(grep -oP '(?<=^version: ")[^"]*' build.yaml)
+if [ "$BUILD_VERSION" != "$VERSION" ]; then
+  echo "ERROR: build.yaml version ($BUILD_VERSION) does not match requested VERSION ($VERSION)." >&2
+  echo "Update build.yaml's version field to match the git tag before releasing." >&2
+  exit 1
+fi
+
+mkdir -p release
+ZIP_NAME="JellyfinSyncPlus_${VERSION}.zip"
+ZIP_PATH="release/${ZIP_NAME}"
+rm -f "$ZIP_PATH"
+(cd src/JellyfinSyncPlus/bin/Release/net9.0 && zip -j "$ROOT/$ZIP_PATH" JellyfinSyncPlus.dll)
+
+CHECKSUM=$(md5sum "$ZIP_PATH" | awk '{print $1}')
+SOURCE_URL="${SERVER_URL}/${REPO_OWNER}/${REPO_NAME}/releases/download/v${VERSION}/${ZIP_NAME}"
+
+python3 "$ROOT/dev/update_manifest.py" \
+  --build-yaml "$ROOT/build.yaml" \
+  --manifest "$ROOT/manifest.json" \
+  --version "$VERSION" \
+  --checksum "$CHECKSUM" \
+  --source-url "$SOURCE_URL"
+
+echo "Packaged $ZIP_PATH"
+echo "Checksum: $CHECKSUM"
+echo "Source URL: $SOURCE_URL"

dev/plugins/JellyfinSyncPlus_0.1.0.0/meta.json

@@ -0,0 +1,13 @@
+{
+  "category": "General",
+  "name": "JellyfinSyncPlus",
+  "description": "Fixes SyncPlay drift via group quality negotiation, host-relay streaming, and active drift correction.",
+  "overview": "Fixes SyncPlay drift via group quality negotiation, host-relay streaming, and active drift correction.",
+  "owner": "cynic",
+  "version": "0.1.0.0",
+  "status": "Active",
+  "autoUpdate": false,
+  "targetAbi": "10.11.6.0",
+  "timestamp": "2026-07-09T00:00:00.0000000Z",
+  "guid": "267dbfe9-bb9c-4eeb-97aa-f0449283cfe6"
+}

dev/update_manifest.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env python3
+"""Appends (or replaces) this build's version entry in manifest.json, using build.yaml
+for the plugin-level metadata (guid, name, description, etc.) and changelog. Run by
+dev/package-release.sh; not meant to be invoked directly outside that flow."""
+import argparse
+import datetime
+import json
+import re
+
+
+def parse_build_yaml(path):
+    # build.yaml is simple enough to not need a real YAML parser dependency.
+    text = open(path, encoding="utf-8").read()
+    fields = {}
+    for key in ("name", "guid", "targetAbi", "framework", "owner", "overview", "category"):
+        m = re.search(rf'^{key}:\s*"([^"]*)"', text, re.MULTILINE)
+        if m:
+            fields[key] = m.group(1)
+
+    def block(key):
+        m = re.search(rf'^{key}:\s*>\s*\n((?:  .*\n?)+)', text, re.MULTILINE)
+        if not m:
+            return ""
+        lines = [line[2:].rstrip() for line in m.group(1).splitlines()]
+        return " ".join(line for line in lines if line).strip()
+
+    fields["description"] = block("description")
+    fields["changelog"] = block("changelog")
+    return fields
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--build-yaml", required=True)
+    parser.add_argument("--manifest", required=True)
+    parser.add_argument("--version", required=True)
+    parser.add_argument("--checksum", required=True)
+    parser.add_argument("--source-url", required=True)
+    args = parser.parse_args()
+
+    build = parse_build_yaml(args.build_yaml)
+
+    try:
+        with open(args.manifest, encoding="utf-8") as f:
+            manifest = json.load(f)
+    except FileNotFoundError:
+        manifest = []
+
+    entry = next((p for p in manifest if p.get("guid") == build["guid"]), None)
+    if entry is None:
+        entry = {
+            "guid": build["guid"],
+            "name": build["name"],
+            "description": build["description"],
+            "overview": build["overview"],
+            "owner": build["owner"],
+            "category": build["category"],
+            "versions": [],
+        }
+        manifest.append(entry)
+    else:
+        entry["description"] = build["description"]
+        entry["overview"] = build["overview"]
+        entry["owner"] = build["owner"]
+        entry["category"] = build["category"]
+
+    entry["versions"] = [v for v in entry["versions"] if v["version"] != args.version]
+    entry["versions"].insert(0, {
+        "version": args.version,
+        "changelog": build["changelog"],
+        "targetAbi": build["targetAbi"],
+        "sourceUrl": args.source_url,
+        "checksum": args.checksum,
+        "timestamp": datetime.datetime.now(datetime.timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ"),
+    })
+
+    with open(args.manifest, "w", encoding="utf-8") as f:
+        json.dump(manifest, f, indent=4)
+        f.write("\n")
+
+    print(f"Updated {args.manifest} with version {args.version}")
+
+
+if __name__ == "__main__":
+    main()