Add managed content and keyboard usage insights

Introduce versioned official content workflows and privacy-safe keyboard analytics, while preventing repeat DeviceCheck sign-ins from incorrectly restricting eligible accounts.

src/main/resources/db/migration/V21__repair_signup_trial_restrictions.sql

@@ -0,0 +1,14 @@
+-- Accounts with an immutable signup-trial grant were incorrectly restricted
+-- when a later sign-in supplied a fresh ephemeral DeviceCheck token.
+UPDATE accounts AS account
+SET
+    account.anti_abuse_restricted = FALSE,
+    account.updated_at = CURRENT_TIMESTAMP(6)
+WHERE account.anti_abuse_restricted = TRUE
+  AND EXISTS (
+      SELECT 1
+      FROM credit_ledger AS ledger
+      WHERE ledger.user_id = account.id
+        AND ledger.entry_type = 'SIGNUP_TRIAL'
+        AND ledger.idempotency_key = CONCAT('internal:signup-trial:', account.id)
+  );

src/main/resources/db/migration/V22__official_content_management.sql

@@ -0,0 +1,55 @@
+-- Official content is immediately published. The singleton catalog row
+-- serializes revision changes and also protects first-write hint versions.
+CREATE TABLE official_content_catalog (
+    id TINYINT UNSIGNED NOT NULL,
+    revision BIGINT UNSIGNED NOT NULL DEFAULT 0,
+    generated_at DATETIME(6) NULL,
+    PRIMARY KEY (id),
+    CONSTRAINT chk_official_content_catalog_singleton CHECK (id = 1)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+
+INSERT INTO official_content_catalog (id, revision, generated_at)
+VALUES (1, 0, NULL);
+
+CREATE TABLE official_skills (
+    id VARCHAR(128) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+    system_image VARCHAR(128) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+    sort_order INT NOT NULL,
+    thinking_enabled BOOLEAN NOT NULL,
+    enabled BOOLEAN NOT NULL DEFAULT FALSE,
+    created_at DATETIME(6) NOT NULL,
+    updated_at DATETIME(6) NOT NULL,
+    PRIMARY KEY (id),
+    KEY idx_official_skills_enabled_sort (enabled, sort_order, id),
+    CONSTRAINT chk_official_skills_id CHECK (id LIKE 'official.%')
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+
+CREATE TABLE official_skill_localizations (
+    skill_id VARCHAR(128) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+    locale VARCHAR(16) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+    name VARCHAR(120) NOT NULL,
+    summary VARCHAR(500) NOT NULL,
+    prompt TEXT NOT NULL,
+    PRIMARY KEY (skill_id, locale),
+    CONSTRAINT fk_official_skill_localizations_skill
+        FOREIGN KEY (skill_id) REFERENCES official_skills (id) ON DELETE CASCADE,
+    CONSTRAINT chk_official_skill_localizations_locale
+        CHECK (locale IN ('zh-Hans', 'en'))
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+
+CREATE TABLE official_hint_packs (
+    locale VARCHAR(8) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+    generated_at DATETIME(6) NULL,
+    expires_at DATETIME(6) NULL,
+    interval_hours INT NULL,
+    version INT UNSIGNED NOT NULL,
+    cards_json MEDIUMTEXT NOT NULL,
+    updated_at DATETIME(6) NOT NULL,
+    PRIMARY KEY (locale),
+    CONSTRAINT chk_official_hint_packs_locale CHECK (locale IN ('zh', 'en')),
+    CONSTRAINT chk_official_hint_packs_interval
+        CHECK (interval_hours IS NULL OR interval_hours BETWEEN 1 AND 168),
+    CONSTRAINT chk_official_hint_packs_version CHECK (version >= 1),
+    CONSTRAINT chk_official_hint_packs_expiry
+        CHECK (expires_at IS NULL OR generated_at IS NULL OR expires_at > generated_at)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

src/main/resources/db/migration/V23__keyboard_usage_daily_summaries.sql

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+-- Privacy-minimized daily counters for text manually committed by OSGKeyboard.
+-- Raw text, key sequences, surrounding context and host application identifiers
+-- are intentionally absent.
+CREATE TABLE keyboard_usage_daily_summaries (
+    id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
+    installation_hash CHAR(64) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+    client_summary_id CHAR(36) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+    summary_date DATE NOT NULL,
+    chinese_character_count BIGINT UNSIGNED NOT NULL,
+    english_character_count BIGINT UNSIGNED NOT NULL,
+    other_character_count BIGINT UNSIGNED NOT NULL,
+    input_session_count BIGINT UNSIGNED NOT NULL,
+    chinese_only_session_count BIGINT UNSIGNED NOT NULL,
+    english_only_session_count BIGINT UNSIGNED NOT NULL,
+    mixed_language_session_count BIGINT UNSIGNED NOT NULL,
+    other_only_session_count BIGINT UNSIGNED NOT NULL,
+    app_version VARCHAR(32) CHARACTER SET ascii COLLATE ascii_bin NULL,
+    os_version VARCHAR(32) CHARACTER SET ascii COLLATE ascii_bin NULL,
+    payload_hash CHAR(64) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
+    received_at DATETIME(6) NOT NULL,
+    PRIMARY KEY (id),
+    UNIQUE KEY uq_keyboard_usage_installation_id (installation_hash, client_summary_id),
+    UNIQUE KEY uq_keyboard_usage_installation_date (installation_hash, summary_date),
+    INDEX ix_keyboard_usage_summary_date (summary_date),
+    CONSTRAINT fk_keyboard_usage_installation
+        FOREIGN KEY (installation_hash)
+        REFERENCES product_analytics_installations (installation_hash)
+        ON DELETE CASCADE,
+    CONSTRAINT chk_keyboard_usage_chinese_count
+        CHECK (chinese_character_count <= 1000000),
+    CONSTRAINT chk_keyboard_usage_english_count
+        CHECK (english_character_count <= 1000000),
+    CONSTRAINT chk_keyboard_usage_other_count
+        CHECK (other_character_count <= 1000000),
+    CONSTRAINT chk_keyboard_usage_session_count
+        CHECK (input_session_count BETWEEN 1 AND 100000),
+    CONSTRAINT chk_keyboard_usage_session_partitions CHECK (
+        chinese_only_session_count <= 100000
+        AND english_only_session_count <= 100000
+        AND mixed_language_session_count <= 100000
+        AND other_only_session_count <= 100000
+        AND chinese_only_session_count
+            + english_only_session_count
+            + mixed_language_session_count
+            + other_only_session_count = input_session_count
+    ),
+    CONSTRAINT chk_keyboard_usage_characters CHECK (
+        chinese_character_count + english_character_count + other_character_count
+            >= input_session_count
+    )
+) ENGINE = InnoDB;