docs(cli): improve --tc-params-file help text with precedence table

- Describe normalisation behaviour (case-insensitive, -/_/. separators)
- Note that unmatched TC IDs are silently skipped
- Add a numbered NOTE block showing the full config precedence chain:
    1. project config  2. --tc-params-file  3. --config  4. -- inline args

Author: rquidute

th_cli/commands/run_tests.py

@@ -90,9 +90,16 @@
     "-m",
     type=click.Path(file_okay=True, dir_okay=False),
     help=colorize_help(
-        "Path to a TC parameters mapping JSON file. "
-        "Maps TC IDs to test_parameters (e.g. int-arg, string-arg, timeout). "
-        "Applied after the project config but before --config overrides and inline -- args."
+        "Path to a JSON file that maps TC IDs to their test_parameters "
+        "(e.g. int-arg, string-arg, timeout). Entries are matched "
+        "case-insensitively with separators - _ . normalised. "
+        "TC IDs not found in the file are silently skipped. "
+        "\n\nNOTE — Configuration precedence (lowest → highest priority):\n"
+        "  1. Project config (persistent, from TH project)\n"
+        "  2. --tc-params-file  ← this option\n"
+        "  3. --config file (execution-only override)\n"
+        "  4. -- inline args  (e.g. -- --int-arg PIXIT.X:1)\n"
+        "\nHigher-priority sources always win on conflicting keys."
     ),
 )
 @click.option(