## ADDED Requirements

### Requirement: JSON output envelope
The system SHALL wrap all successful command output in a JSON envelope with the structure `{"data": <result>, "error": null}`. The system SHALL wrap all error output in a JSON envelope with the structure `{"data": null, "error": "<message>"}`. The envelope SHALL be written to stdout. The `data` field SHALL contain the direct result of the command (object or array). The `error` field SHALL be null on success and a string message on failure.

#### Scenario: Successful command output
- **WHEN** a command completes successfully in JSON format
- **THEN** stdout SHALL contain `{"data": <result>, "error": null}`
- **AND** the process SHALL exit with code 0

#### Scenario: Error command output
- **WHEN** a command fails in JSON format
- **THEN** stdout SHALL contain `{"data": null, "error": "<message>"}`
- **AND** the process SHALL exit with code 1

#### Scenario: Envelope structure is consistent
- **WHEN** any command is executed in JSON format
- **THEN** the output SHALL always contain exactly the keys `data` and `error` at the top level

### Requirement: Table format output
The system SHALL support a `--format=table` flag that outputs results as human-readable tabular text. Table output SHALL be written to stdout. Table output SHALL NOT use the JSON envelope. When table format is active and an error occurs, the error message SHALL be written to stderr (not stdout). Each resource type SHALL define its own column set for table rendering.

#### Scenario: Table output for a list of items
- **WHEN** a list command is executed with `--format=table`
- **THEN** stdout SHALL contain a header row followed by one row per item
- **AND** columns SHALL be aligned and separated by whitespace

#### Scenario: Table output for a single item
- **WHEN** a get command is executed with `--format=table`
- **THEN** stdout SHALL contain a key-value representation of the item

#### Scenario: Error in table format
- **WHEN** a command fails with `--format=table`
- **THEN** the error message SHALL be written to stderr
- **AND** the process SHALL exit with code 1

### Requirement: Format flag default
The system SHALL default to JSON format when no `--format` flag is provided. The `--format` flag SHALL accept values `json` and `table`. Any other value SHALL cause an error and exit with code 1.

#### Scenario: Default format is JSON
- **WHEN** a command is executed without `--format`
- **THEN** the output SHALL be in JSON envelope format

#### Scenario: Explicit JSON format
- **WHEN** a command is executed with `--format=json`
- **THEN** the output SHALL be in JSON envelope format

#### Scenario: Explicit table format
- **WHEN** a command is executed with `--format=table`
- **THEN** the output SHALL be in table format

#### Scenario: Invalid format value
- **WHEN** a command is executed with `--format=xml`
- **THEN** the system SHALL print an error and exit with code 1

### Requirement: Log output separation
All log output SHALL be written to stderr using structured JSON via `log/slog`. Log output SHALL never appear on stdout. This ensures that stdout contains only the command's data output (JSON envelope or table) and is safe to pipe or parse programmatically.

#### Scenario: Logs do not pollute stdout
- **WHEN** a command is executed with `--log-level=debug`
- **THEN** all log entries SHALL appear on stderr
- **AND** stdout SHALL contain only the command's data output

#### Scenario: Logs are structured JSON
- **WHEN** a log entry is emitted
- **THEN** it SHALL be a valid JSON object with at minimum `time`, `level`, and `msg` fields