feat(cli): support generator index lists and ranges (#3071)

[annacastroops]

Fixes #3071

Extend generator filtering (-g / --generator-index / g: path filters) to accept comma-separated indices and closed ranges such as 1,3,6-10.

Changes

• Add parseGeneratorIndexSpec() with validation for monotonic, non-overlapping specs.
• Update CLI parsing and generator tracker runtime to iterate filtered indices.
• Add parser and CLI regression tests.

Accepted examples

• -g 1,2
• -g 1-3
• -g 1,3,6-10

Rejected examples

• -g 1-3,2-4 (overlap)
• -g 3,2,1 (bad order)
• -g 3-1 (decreasing range)
• -g 1,2,2,3 (duplicate)
• -g -2, -g 1--2, -g 1-2-3

Test plan

• GeneratorFilterParser.tests.cpp
• CmdLine.tests.cpp generator filter sections