refactor: "install" page (#39400)

1. remove useless options
2. set AppDataPath instead of repo root path
3. make "disable self-registration" default enabled
4. avoid writing corrupted ini file
5. avoid auto-sign-in the existing admin user

options/locale/locale_en-US.json

@@ -244,6 +244,7 @@
   "install.installing_desc": "Installing now, please wait…",
   "install.title": "Initial Configuration",
   "install.docker_helper": "If you run Gitea inside Docker, please read the <a target=\"_blank\" rel=\"noopener noreferrer\" href=\"%s\">documentation</a> before changing any settings.",
+  "install.config_edit_helper": "To fine tune more details: edit the configuration file after installation. Reference: <a target=\"_blank\" href=\"%s\">app.example.ini</a>.",
   "install.require_db_desc": "Gitea requires MySQL, PostgreSQL, MSSQL, SQLite3 or TiDB (MySQL protocol).",
   "install.db_title": "Database Settings",
   "install.db_type": "Database Type",
@@ -263,6 +264,7 @@
   "install.reinstall_confirm_check_3": "You confirm that you are absolutely sure that this Gitea is running with the correct app.ini location and that you are sure that you have to re-install. You confirm that you acknowledge the above risks.",
   "install.err_empty_db_path": "The SQLite3 database path cannot be empty.",
   "install.no_admin_and_disable_registration": "You cannot disable user self-registration without creating an administrator account.",
+  "install.admin_user_recreation_disallowed": "You cannot re-create an admin user since the database user table is not empty, you can use 'gitea admin user ...' sub-commands to manage admin users after installation.",
   "install.err_empty_admin_password": "The administrator password cannot be empty.",
   "install.err_empty_admin_email": "The administrator email address cannot be empty.",
   "install.err_admin_name_is_reserved": "Administrator username is invalid. Username is reserved.",
@@ -271,22 +273,18 @@
   "install.general_title": "General Settings",
   "install.app_name": "Site Title",
   "install.app_name_helper": "You can enter your company name here.",
-  "install.repo_path": "Repository Root Path",
-  "install.repo_path_helper": "Remote Git repositories will be saved to this directory.",
-  "install.lfs_path": "Git LFS Root Path",
-  "install.lfs_path_helper": "Files tracked by Git LFS will be stored in this directory. Leave empty to disable.",
+  "install.app_data_path": "Data Path",
+  "install.app_data_path_helper": "Most Gitea data will be saved to this directory.",
   "install.run_user": "Run As Username",
   "install.run_user_helper": "The operating system username that Gitea runs as, it must have write access to the data paths. This value is auto-detected and cannot be changed here. To use a different user, restart Gitea under that account.",
   "install.domain": "Server Domain",
   "install.domain_helper": "Domain or host address for the server.",
   "install.ssh_port": "SSH Server Port",
   "install.ssh_port_helper": "Port number your SSH server listens on. Leave empty to disable.",
-  "install.http_port": "Gitea HTTP Listen Port",
+  "install.http_port": "HTTP Server Port",
   "install.http_port_helper": "Port number the Gitea web server will listen on.",
-  "install.app_url": "Gitea Base URL",
-  "install.app_url_helper": "Base address for HTTP(S) clone URLs and email notifications.",
-  "install.log_root_path": "Log Path",
-  "install.log_root_path_helper": "Log files will be written to this directory.",
+  "install.app_url": "Gitea Website URL",
+  "install.app_url_helper": "Gitea web application's public URL for HTTP(S) access, clone URLs and email notifications.",
   "install.optional_title": "Optional Settings",
   "install.email_title": "Email Settings",
   "install.smtp_addr": "SMTP Host",
@@ -299,17 +297,11 @@
   "install.register_confirm": "Require Email Confirmation to Register",
   "install.mail_notify": "Enable Email Notifications",
   "install.server_service_title": "Server and Third-Party Service Settings",
-  "install.disable_registration": "Disable Self-Registration",
-  "install.disable_registration_popup": "Disable user self-registration. Only administrators will be able to create new user accounts.",
-  "install.allow_only_external_registration_popup": "Allow Registration Only Through External Services",
-  "install.openid_signin": "Enable OpenID Sign-In",
-  "install.openid_signin_popup": "Enable user sign-in via OpenID.",
-  "install.openid_signup": "Enable OpenID Self-Registration",
-  "install.openid_signup_popup": "Enable OpenID-based user self-registration.",
+  "install.disable_registration": "Only administrators can create user accounts (no self-registration)",
   "install.enable_captcha": "Enable registration CAPTCHA",
   "install.enable_captcha_popup": "Require a CAPTCHA for user self-registration.",
-  "install.require_sign_in_view": "Require Sign-In to View Pages",
-  "install.require_sign_in_view_popup": "Limit page access to signed-in users. Visitors will only see the sign-in and registration pages.",
+  "install.require_sign_in_view": "Require sign-in to view pages (recommended for private instances)",
+  "install.require_sign_in_view_popup": "Limit page access to signed-in users. Anonymous visitors will only see the sign-in and registration pages.",
   "install.admin_setting_desc": "Creating an administrator account is optional. The first registered user will automatically become an administrator.",
   "install.admin_title": "Administrator Account Settings",
   "install.admin_name": "Administrator Username",
@@ -320,7 +312,6 @@
   "install.test_git_failed": "Could not test 'git' command: %v",
   "install.invalid_db_setting": "The database settings are invalid: %v",
   "install.invalid_db_table": "The database table \"%s\" is invalid: %v",
-  "install.invalid_repo_path": "The repository root path is invalid: %v",
   "install.invalid_app_data_path": "The app data path is invalid: %v",
   "install.internal_token_failed": "Failed to generate internal token: %v",
   "install.secret_key_failed": "Failed to generate secret key: %v",
@@ -331,15 +322,9 @@
   "install.default_keep_email_private_popup": "Hide email addresses of new user accounts by default.",
   "install.default_allow_create_organization": "Allow Creation of Organizations by Default",
   "install.default_allow_create_organization_popup": "Allow new user accounts to create organizations by default.",
-  "install.default_enable_timetracking": "Enable Time Tracking by Default",
-  "install.default_enable_timetracking_popup": "Enable time tracking for new repositories by default.",
   "install.no_reply_address": "Hidden Email Domain",
   "install.no_reply_address_helper": "Domain name for users with a hidden email address. For example, the username 'joe' will be logged in Git as 'joe@noreply.example.org' if the hidden email domain is set to 'noreply.example.org'.",
-  "install.password_algorithm": "Password Hash Algorithm",
-  "install.invalid_password_algorithm": "Invalid password hash algorithm",
-  "install.password_algorithm_helper": "Set the password hashing algorithm. Algorithms have differing requirements and strengths. The argon2 algorithm is rather secure but uses a lot of memory and may be inappropriate for small systems.",
-  "install.enable_update_checker": "Enable Update Checker",
-  "install.enable_update_checker_helper": "Checks for new version releases periodically by connecting to gitea.io.",
+  "install.enable_update_checker": "Enable update checker",
   "install.env_config_keys": "Environment Configuration",
   "install.env_config_keys_prompt": "The following environment variables will also be applied to your configuration file:",
   "install.config_write_file_prompt": "These configuration options will be written into: %s",