## ADDED Requirements

### Requirement: Host Agent requires a local account before unattended operation
The Host Agent SHALL refuse to start its background polling loop until a local account (username and hashed password) exists on disk, and SHALL provide an explicit interactive command to create that account.

#### Scenario: No local account exists and setup is run interactively
- **WHEN** an operator runs the Host Agent's setup command on a machine with no local account file
- **THEN** the process prompts for a username and password, persists a hashed credential, and does not echo the password back

#### Scenario: Local account already exists
- **WHEN** the Host Agent's default (run) command starts and a valid local account file is already present
- **THEN** the process starts background polling immediately without prompting for any credential

#### Scenario: No local account exists and the process has no interactive terminal
- **WHEN** the Host Agent's default (run) command starts with no local account file and no controlling terminal available
- **THEN** the process exits with an error identifying the setup command to run, without hanging or prompting

### Requirement: Local account credentials are stored hashed and access-restricted
The Host Agent SHALL persist the local account password only as a salted hash, never in plaintext, and SHALL restrict the credential file's filesystem permissions to the owning user.

#### Scenario: Local account file is written
- **WHEN** the setup command creates a new local account
- **THEN** the persisted file contains the username, a random per-account salt, an iteration count, and a derived password hash, and contains no plaintext password

#### Scenario: Local account file permissions
- **WHEN** the Host Agent writes or rewrites the local account file
- **THEN** the file is only readable and writable by the owning user

#### Scenario: Local account file is corrupted or unreadable
- **WHEN** the Host Agent attempts to load a local account file that is not valid, readable JSON in the expected shape
- **THEN** the process reports a clear error and does not start background polling