feat: add admin publishing workflow and yar theme

Add Go/Postgres admin APIs, Angular admin UI, manual build flow, asset uploads, markdown import/export, configurable slug generation, and the Yar reading theme. Exclude local docs and generated development artifacts from version control.

backend/migrations/001_admin_schema.sql

@@ -0,0 +1,100 @@
+CREATE EXTENSION IF NOT EXISTS pgcrypto;
+
+CREATE TABLE IF NOT EXISTS users (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    username TEXT NOT NULL UNIQUE,
+    password_hash TEXT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    last_login_at TIMESTAMPTZ
+);
+
+CREATE TABLE IF NOT EXISTS posts (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    slug TEXT NOT NULL UNIQUE,
+    title TEXT NOT NULL,
+    summary TEXT NOT NULL DEFAULT '',
+    body_markdown TEXT NOT NULL DEFAULT '',
+    status TEXT NOT NULL DEFAULT 'draft',
+    cover TEXT NOT NULL DEFAULT '',
+    version INTEGER NOT NULL DEFAULT 1,
+    slug_source TEXT NOT NULL DEFAULT 'manual',
+    slug_locked BOOLEAN NOT NULL DEFAULT false,
+    published_at TIMESTAMPTZ,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    deleted_at TIMESTAMPTZ,
+    CONSTRAINT posts_status_check CHECK (status IN ('draft', 'published', 'archived', 'deleted')),
+    CONSTRAINT posts_version_check CHECK (version >= 1)
+);
+
+CREATE INDEX IF NOT EXISTS idx_posts_status ON posts(status);
+CREATE INDEX IF NOT EXISTS idx_posts_published_at ON posts(published_at DESC);
+CREATE INDEX IF NOT EXISTS idx_posts_updated_at ON posts(updated_at DESC);
+
+CREATE TABLE IF NOT EXISTS post_versions (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    post_id UUID NOT NULL REFERENCES posts(id) ON DELETE CASCADE,
+    version INTEGER NOT NULL,
+    title TEXT NOT NULL,
+    summary TEXT NOT NULL,
+    body_markdown TEXT NOT NULL,
+    status TEXT NOT NULL,
+    reason TEXT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    created_by UUID REFERENCES users(id) ON DELETE SET NULL,
+    CONSTRAINT post_versions_status_check CHECK (status IN ('draft', 'published', 'archived', 'deleted')),
+    CONSTRAINT post_versions_reason_check CHECK (reason IN ('save', 'publish', 'unpublish', 'archive', 'restore', 'import', 'rollback')),
+    CONSTRAINT post_versions_version_check CHECK (version >= 1),
+    UNIQUE (post_id, version)
+);
+
+CREATE INDEX IF NOT EXISTS idx_post_versions_post_id_created_at ON post_versions(post_id, created_at DESC);
+
+CREATE TABLE IF NOT EXISTS tags (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name TEXT NOT NULL UNIQUE,
+    slug TEXT NOT NULL UNIQUE,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE TABLE IF NOT EXISTS post_tags (
+    post_id UUID NOT NULL REFERENCES posts(id) ON DELETE CASCADE,
+    tag_id UUID NOT NULL REFERENCES tags(id) ON DELETE CASCADE,
+    PRIMARY KEY (post_id, tag_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_post_tags_tag_id ON post_tags(tag_id);
+
+CREATE TABLE IF NOT EXISTS build_jobs (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    trigger TEXT NOT NULL,
+    status TEXT NOT NULL DEFAULT 'queued',
+    post_id UUID REFERENCES posts(id) ON DELETE SET NULL,
+    started_at TIMESTAMPTZ,
+    finished_at TIMESTAMPTZ,
+    log TEXT NOT NULL DEFAULT '',
+    error TEXT NOT NULL DEFAULT '',
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    created_by UUID REFERENCES users(id) ON DELETE SET NULL,
+    CONSTRAINT build_jobs_trigger_check CHECK (trigger IN ('publish', 'manual', 'import', 'sync')),
+    CONSTRAINT build_jobs_status_check CHECK (status IN ('queued', 'running', 'success', 'failed', 'cancelled'))
+);
+
+CREATE INDEX IF NOT EXISTS idx_build_jobs_status_created_at ON build_jobs(status, created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_build_jobs_post_id_created_at ON build_jobs(post_id, created_at DESC);
+
+CREATE TABLE IF NOT EXISTS assets (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    path TEXT NOT NULL UNIQUE,
+    original_name TEXT NOT NULL,
+    mime_type TEXT NOT NULL,
+    size_bytes BIGINT NOT NULL,
+    sha256 TEXT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    created_by UUID REFERENCES users(id) ON DELETE SET NULL,
+    CONSTRAINT assets_size_bytes_check CHECK (size_bytes >= 0)
+);
+
+CREATE INDEX IF NOT EXISTS idx_assets_sha256 ON assets(sha256);

backend/migrations/002_admin_sessions.sql

@@ -0,0 +1,11 @@
+CREATE TABLE IF NOT EXISTS admin_sessions (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    token_hash TEXT NOT NULL UNIQUE,
+    expires_at TIMESTAMPTZ NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    last_seen_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS idx_admin_sessions_user_id ON admin_sessions(user_id);
+CREATE INDEX IF NOT EXISTS idx_admin_sessions_expires_at ON admin_sessions(expires_at);