Add programmatic SDK and refactor mt5cli into cli, sdk, and utils (#15)

* Refactor cli.py into cli and utils modules

Extract constants, enums, Click parameter types, and parse/export utility
functions into a new mt5cli/utils.py module, keeping the typer app, commands,
and collect-history SQLite helpers in cli.py.

https://claude.ai/code/session_016JwSEhPyq6phXySktQ1FGU

* Address review comments

* Add programmatic SDK layer for read-only MT5 data collection.

Expose Mt5CliClient and collect_history through the package API while keeping CLI commands as thin adapters over the SDK.

Co-authored-by: Cursor <cursoragent@cursor.com>

* Harden SDK connection lifecycle and scope internal helpers as private.

Co-authored-by: Cursor <cursoragent@cursor.com>

* Export build_config in the public API and bump version to 0.4.0.

Co-authored-by: Cursor <cursoragent@cursor.com>

* Remove duplicate scripts/ in favor of local-qa skill script.

Co-authored-by: Cursor <cursoragent@cursor.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

docs/api/index.md

@@ -10,12 +10,22 @@ The mt5cli package consists of the following modules:
 
 Command-line interface module providing typer-based commands for exporting MetaTrader 5 data to CSV, JSON, Parquet, and SQLite3 formats.
 
+### [Utils](utils.md)
+
+Utility module providing constants, enums, Click parameter types, and helper functions for parsing and exporting data.
+
+### [SDK](sdk.md)
+
+Programmatic SDK for read-only MetaTrader 5 data collection. Returns pandas DataFrames and provides `collect_history` for SQLite bulk collection.
+
 ## Architecture Overview
 
 The package follows a simple architecture built on top of pdmt5:
 
-1. **CLI Layer** (`cli.py`): Typer application with subcommands for each data type, custom Click parameter types for datetime/timeframe/tick flags parsing, and format detection/export utilities.
-2. **Data Layer** (via `pdmt5`): Uses `Mt5DataClient` and `Mt5Config` from the pdmt5 package for all MetaTrader 5 data access.
+1. **CLI Layer** (`cli.py`): Typer application with subcommands that delegate to the SDK and export results.
+2. **SDK Layer** (`sdk.py`): Read-only data access functions, `Mt5CliClient`, and `collect_history` orchestration.
+3. **Utils Layer** (`utils.py`): Constants, enums, custom Click parameter types, parsing helpers, and format detection/export utilities.
+4. **Data Layer** (via `pdmt5`): Uses `Mt5DataClient` and `Mt5Config` from the pdmt5 package for all MetaTrader 5 data access.
 
 ## Usage Guidelines
 
@@ -47,15 +57,38 @@ mt5cli -o data.db --table symbols symbols --group "*USD*"
 ## Python API
 
 ```python
-from mt5cli import detect_format, export_dataframe
-import pandas as pd
+from datetime import UTC, datetime
+from pathlib import Path
+
+from mt5cli import (
+    Mt5CliClient,
+    collect_history,
+    copy_rates_range,
+    detect_format,
+    export_dataframe,
+)
+
+# Fetch rates programmatically
+rates = copy_rates_range(
+    "EURUSD",
+    timeframe="H1",
+    date_from="2024-01-01",
+    date_to="2024-02-01",
+)
 
 # Detect output format from file extension
 fmt = detect_format(Path("output.parquet"))  # Returns "parquet"
 
 # Export a DataFrame
-df = pd.DataFrame({"symbol": ["EURUSD"], "bid": [1.1234]})
-export_dataframe(df, Path("output.csv"), "csv")
+export_dataframe(rates, Path("output.csv"), "csv")
+
+# Collect history into SQLite
+collect_history(
+    Path("history.db"),
+    symbols=["EURUSD"],
+    date_from=datetime(2024, 1, 1, tzinfo=UTC),
+    date_to=datetime(2024, 2, 1, tzinfo=UTC),
+)
 ```
 
 ## Examples

docs/api/sdk.md

@@ -0,0 +1,3 @@
+# SDK Module
+
+::: mt5cli.sdk

docs/api/utils.md

@@ -0,0 +1,3 @@
+# Utils Module
+
+::: mt5cli.utils