Add documentation for log file path resolution behavior

Document that relative paths in logging_config.ini are automatically
resolved against the application directory, not the process CWD.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: nicolasbisurgi

docs/advanced/settings-reference.md

@@ -91,6 +91,18 @@ By default, RushTI writes `rushti.log` to the application root directory (next t
 
 See `config/logging_config.ini` for the full configuration.
 
+#### Log File Path Resolution
+
+Relative file paths in `logging_config.ini` (e.g., `'rushti.log'`) are automatically resolved against the **application directory** — not the current working directory. This means the log file is always created in the expected location, even when RushTI is invoked from a different directory (e.g., via TM1's `ExecuteCommand` where the working directory is typically `C:\windows\system32`).
+
+The application directory is determined by:
+
+1. `RUSHTI_DIR` environment variable (if set)
+2. The directory containing the executable (for standalone `.exe` builds)
+3. The project root (for pip-installed scripts)
+
+If you specify an **absolute path** in `logging_config.ini` (e.g., `'E:/logs/rushti.log'`), it is used as-is.
+
 !!! tip "Choosing a Log Level"
     - **DEBUG**: Full worker activity, task scheduling decisions, connection details. Use for troubleshooting.
     - **INFO**: Normal operations -- task starts/completions, run summary. Default for production.

docs/features/tm1-integration.md

@@ -315,6 +315,9 @@ ExecuteCommand(cmd, 1);
     - **Always use `cmd /c`** — TM1's `ExecuteCommand` does not invoke a shell by default. Wrapping with `cmd /c` ensures the command runs in a proper shell environment.
     - **Use `ExecuteCommand(cmd, 1)`** — The second parameter `1` makes TM1 wait for RushTI to complete before continuing the TI process.
 
+!!! note "Log File Location"
+    When launched from `ExecuteCommand`, the process working directory is typically `C:\windows\system32`. RushTI automatically resolves relative log file paths (configured in `logging_config.ini`) against the application directory (`RUSHTI_DIR` or the exe directory), so `rushti.log` is created in the correct location regardless of the working directory. See [Logging](../advanced/settings-reference.md#logging) for details.
+
 ---
 
 ## Customize Further