improve --filter help text readability with sections and examples

        default=None,

        metavar="TOKEN",

        help=(

            "Select which tests to run. Accepts any combination of the following tokens: "

            "(1) Level: LEVEL1, LEVEL2, LEVEL3 (default: LEVEL3 = no bitrate restrictions). "

            "LEVEL1 restricts ENC to <=80 kbps and DEC to EXT<=80 kbps, MONO and STEREO outputs. "

            "LEVEL2 uses the same rules as LEVEL1 but with <=192 kbps for ENC and DEC EXT. "

            "(2) Tag: ENC, DEC, REND, ISAR, ISAR_ENC — selects specific test groups. "

            "Prefix with + to add groups and with - to remove groups at any level. "

            "Under LEVEL1, the default tag baseline is ENC+DEC when no plain tag is provided. "

            "(3) Output format (ENC/DEC): MONO, STEREO, BINAURAL, BINAURAL_ROOM_IR, "

            "BINAURAL_ROOM_REVERB, 5_1, 7_1, 5_1_4, 5_1_2, 7_1_4, FOA, HOA2, HOA3, EXT. "

            "Aliases: HOA -> HOA2+HOA3, SBA -> FOA+HOA2+HOA3, MC -> 5_1+7_1+5_1_4+5_1_2+7_1_4. "

            "Wildcard prefixes are also supported for tags/formats (e.g., ISAR*, BINAURAL*). "

            "These tokens restrict ENC/DEC tests at any level by output format; under LEVEL1/LEVEL2 they apply on top of level constraints. "

            "(4) Substring: any other plain token is matched case-insensitively against the test "

            "command line. Multiple plain tokens are combined with logical AND. "

            "Prefix a token with + to add matching tests to the selection, "

            "or with - to remove matching tests from the selection. "

            "Examples: "

            "'--filter LEVEL1' — run LEVEL1 ENC+DEC; "

            "'--filter LEVEL2' — run LEVEL2 ENC+DEC; "

            "'--filter LEVEL1 DEC MONO' — run only MONO tests from the LEVEL1 DEC set; "

            "'--filter LEVEL2 DEC MONO' — run only MONO tests from the LEVEL2 DEC set; "

            "'--filter +REND -ISAR' — at default LEVEL3 baseline (ENC+DEC), add all REND tests and remove all ISAR tests; "

            "'--filter LEVEL1 +REND' — run LEVEL1 ENC+DEC and also all REND tests; "

            "'--filter LEVEL2 +REND' — run LEVEL2 ENC+DEC and also all REND tests; "

            "'--filter DEC HOA' — run DEC tests with HOA2/HOA3 outputs; "

            "'--filter DEC SBA' — run DEC tests with FOA/HOA2/HOA3 outputs; "

            "'--filter DEC MC' — run DEC tests with multichannel outputs (5_1, 7_1, 5_1_4, 5_1_2, 7_1_4); "

            "'--filter ISAR*' — run ISAR and ISAR_ENC groups; "

            "'--filter DEC BINAURAL*' — run DEC tests for all BINAURAL* output formats; "

            "'--filter DEC JBM' — run DEC tests containing 'JBM'; "

            "'--filter DEC +BINAURAL' — run all DEC tests plus those containing 'BINAURAL'; "

            "'--filter DEC -voip' — run all DEC tests except those containing 'voip'."

            "Select which tests to run. Default baseline: ENC+DEC tests.\n"

            "\n"

            "TOKEN TYPES:\n"

            "  LEVEL1, LEVEL2, LEVEL3      — Test level (default: LEVEL3). LEVEL1: ≤80 kbps; LEVEL2: ≤192 kbps; LEVEL3: unlimited.\n"

            "  ENC, DEC, REND, ISAR*       — Test groups (∗=optional). Prefix +/- to add/remove.\n"

            "  MONO, STEREO, EXT, HOA*, SBA, MC    — Output format (ENC/DEC only). Aliases: HOA→HOA2+HOA3, SBA→FOA+HOA2+HOA3, MC→{5_1,7_1,…}.\n"

            "  (other)                     — Substring (case-insensitive, matched against command). Multiple terms use AND logic. Prefix +/- to add/remove.\n"

            "  *, +*, -*                   — Wildcard tags/formats (e.g., ISAR*, BINAURAL*). Prefix +/- to add/remove.\n"

            "\n"

            "EXAMPLES:\n"

            "  --filter LEVEL1                    Run LEVEL1 ENC+DEC (≤80 kbps).\n"

            "  --filter LEVEL2                    Run LEVEL2 ENC+DEC (≤192 kbps).\n"

            "  --filter LEVEL1 DEC MONO           Run LEVEL1 DEC MONO tests only.\n"

            "  --filter +REND +ISAR               Add REND and ISAR to default ENC+DEC.\n"

            "  --filter DEC HOA                   Run DEC tests with HOA2/HOA3 outputs.\n"

            "  --filter DEC +BINAURAL             Run all LEVEL3 DEC tests plus BINAURAL variant matches.\n"

            "  --filter DEC JBM +BINAURAL         Run JBM DEC tests + BINAURAL-variant tests.\n"

            "  --filter DEC -voip                 Run all LEVEL3 DEC tests except those matching 'voip'.\n"

        ),

    )

    parser.add_argument(