Golden captures of SaaS filter-rules and netmaps across the ACL,
grant, routes, and SSH corpora. These back the data-driven compat tests
that verify headscale's policy output against Tailscale SaaS verbatim.
Updates #3157
Rename all 594 test data files from .json to .hujson and add
descriptive header comments to each file documenting what policy
rules are under test and what outcome is expected.
Update test loaders in all 5 _test.go files to parse HuJSON via
hujson.Parse/Standardize/Pack before json.Unmarshal.
Add cross-dependency warning to via_compat_test.go documenting
that GRANT-V29/V30/V31/V36 are shared with TestGrantsCompat.
Add .gitignore exemption for testdata HuJSON files.
Add routable_ips and approved_routes fields to the node topology
definitions in all golden test files. These represent the subnet
routes actually advertised by nodes on the Tailscale SaaS network
during data capture:
Routes topology (92 files, 6 router nodes):
big-router: 10.0.0.0/8
subnet-router: 10.33.0.0/16
ha-router1: 192.168.1.0/24
ha-router2: 192.168.1.0/24
multi-router: 172.16.0.0/24
exit-node: 0.0.0.0/0, ::/0
ACL topology (199 files, 1 router node):
subnet-router: 10.33.0.0/16
Grants topology (203 files, 1 router node):
subnet-router: 10.33.0.0/16
The route assignments were deduced from the golden data by analyzing
which router nodes receive FilterRules for which destination CIDRs
across all test files, and cross-referenced with the MTS setup
script (setup_grant_nodes.sh).
Updates #2180
Replace 9,937 lines of inline Go test expectations with 215 JSON golden files captured from Tailscale SaaS. The new data-driven test driver compares headscale's filter compilation output against real Tailscale behavior for each node in an 8-node topology.
Updates #2180
