DBA-291 Refactor databao-cli: Phase 1

[catstrike]

Refactor CLI command structure — move command definitions out of main.py into their own modules
__main__.py containes the full Click command definitions (decorators, options, arguments, docstrings, and handler bodies) for all CLI commands alongside their business logic. This makes __main__.py a 335-line file that mixes wiring and implementation, making it harder to locate command-specific code.

• Each command module under commands/ should own both its *_impl function (business logic) and its @click.command() definition. Command groups should follow the same pattern via their package __init__.py
• __main__.py should be reduced to wiring only: the root cli group, and a COMMANDS list
• Update docs/architecture.md to document the new structure and extension points

[Copilot]

Pull request overview

Refactors Databao CLI command organization by moving Click command definitions into their respective command modules and slimming __main__.py down to CLI wiring/registration, with accompanying architecture documentation updates.

Changes:

• Moved Click decorators/handlers for commands (e.g., ask, build, index, init, status, app, mcp) into src/databao_cli/commands/*.
• Introduced a shared CLI utility helper (get_project_or_exit) to centralize “find project” handling.
• Updated docs/architecture.md to document the new CLI command structure and registration approach.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/databao_cli/main.py	Reduced to root Click group + centralized COMMANDS registration wiring.
src/databao_cli/commands/_utils.py	Adds shared helper for resolving a project (or exiting).
src/databao_cli/commands/status.py	Adds Click command wrapper; switches implementation to use get_project_or_exit.
src/databao_cli/commands/init.py	Adds Click command wrapper around existing init implementation and interactive flow.
src/databao_cli/commands/build.py	Adds Click command wrapper for build behavior.
src/databao_cli/commands/index.py	Adds Click command wrapper for indexing behavior.
src/databao_cli/commands/ask.py	Adds Click command wrapper and adjusts ask_impl signature to accept a project path.
src/databao_cli/commands/app.py	Adds Click command wrapper; reworks app_impl to accept explicit args/options.
src/databao_cli/commands/mcp.py	Adds Click command wrapper for MCP server start.
src/databao_cli/commands/datasource/init.py	Introduces datasource group and subcommands (add, check) in-package.
docs/architecture.md	Documents new project/CLI structure and command registration mechanism.

Comments suppressed due to low confidence (2)

src/databao_cli/commands/status.py:34

• status_impl() now calls get_project_or_exit(), which sys.exit(1)s when no Databao project is found. This breaks existing behavior where databao status can run outside a project (see tests) and also breaks UI usage (ui/services/dce_operations.get_status_info() imports and calls status_impl()), since exiting would terminate the Streamlit process. Consider keeping status_impl() non-exiting (use find_project() and include domain info only when available), and apply the “exit if missing” behavior only in the Click command wrapper if desired.

def status_impl(project_dir: Path) -> str:
    project_layout = get_project_or_exit(project_dir)

    dce_info = get_databao_context_engine_info()

    return _generate_info_string(
        dce_info,
        [get_databao_context_engine_domain_info(domain) for domain in project_layout.get_domain_dirs()]
        if project_layout
        else [],
    )

docs/architecture.md:66

• This update removes the previously documented “Database Support” details (supported databases / optional deps) from the architecture doc. If that information is still accurate, consider re-adding it here or linking to the new canonical location so users don’t lose guidance on supported backends.

## Extension Points
- Add CLI command: create module in `commands/`, register with Click group
  in `__main__.py`.
- Add MCP tool: add handler in `mcp/tools/`, register in `mcp/server.py`.
- Add datasource type: extend via `databao-context-engine` optional deps.
- Add UI page: add to `ui/pages/`.

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[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

src/databao_cli/commands/status.py:34

• status_impl() now calls get_project_or_exit(), which exits with code 1 when run outside a Databao project. This changes the CLI behavior and breaks the existing contract verified by tests/test_status.py (it invokes databao status in an empty temp dir and expects exit_code == 0 with engine/plugin info). Consider using find_project(project_dir) here and only adding domain info when a project is found, while still returning system-wide DCE info when no project exists.

def status_impl(project_dir: Path) -> str:
    project_layout = get_project_or_exit(project_dir)

    dce_info = get_databao_context_engine_info()

    return _generate_info_string(
        dce_info,
        [get_databao_context_engine_domain_info(domain) for domain in project_layout.get_domain_dirs()]
        if project_layout
        else [],
    )

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[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

src/databao_cli/commands/status.py:34

• status_impl() now calls get_project_or_exit(), which will sys.exit(1) when run outside a Databao project. This breaks databao status in a non-project directory (see tests expecting exit_code==0) and can also terminate callers like ui/services/dce_operations.get_status_info(). Use find_project() (allowing None) in status_impl, and keep the “no project” behavior as “system-wide info only” rather than exiting; also remove the now-dead if project_layout else [] branch once project_layout is optional again.

@click.command()
@click.pass_context
def status(ctx: click.Context) -> None:
    """Display project status and system-wide information."""
    click.echo(status_impl(ctx.obj["project_dir"]))


def status_impl(project_dir: Path) -> str:
    project_layout = get_project_or_exit(project_dir)

    dce_info = get_databao_context_engine_info()

    return _generate_info_string(
        dce_info,
        [get_databao_context_engine_domain_info(domain) for domain in project_layout.get_domain_dirs()]
        if project_layout
        else [],
    )

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[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

src/databao_cli/commands/datasource/check.py:51

• fq_datasource_name is built using os.pathsep, which is platform-dependent (; on Windows). This output looks like a logical identifier (and tests expect root:...), so using a fixed separator (e.g., ':') would keep CLI output stable across platforms.

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[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

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