Compile grant app fields into CapGrant FilterRules matching Tailscale
SaaS behavior. Key changes:
- Generate CapGrant rules in compileFilterRules and
compileGrantWithAutogroupSelf, with node-specific /32 and /128
Dsts for autogroup:self grants
- Add reversed companion rules for drive→drive-sharer and
relay→relay-target capabilities, ordered by original cap name
- Narrow broad CapGrant Dsts to node-specific prefixes in
ReduceFilterRules via new reduceCapGrantRule helper
- Skip merging CapGrant rules in mergeFilterRules to preserve
per-capability structure
- Remove ip+app mutual exclusivity validation (Tailscale accepts both)
- Add semantic JSON comparison for RawMessage types and netip.Prefix
comparators in test infrastructure
Reduces grant compat test skips from 99 to 41 (58 newly passing).
Updates #2180
Per Tailscale documentation, the wildcard (*) source includes "any
approved subnets" — the actually-advertised-and-approved routes from
nodes, not the autoApprover policy prefixes.
Change Asterix.resolve() to return just the base CGNAT+ULA set, and
add approved subnet routes as separate SrcIPs entries in the filter
compilation path. This preserves individual route prefixes that would
otherwise be merged by IPSet (e.g., 10.0.0.0/8 absorbing 10.33.0.0/16).
Also swap rule ordering in compileGrantWithAutogroupSelf() to emit
non-self destination rules before autogroup:self rules, matching the
Tailscale FilterRule wire format ordering.
Remove the unused AutoApproverPolicy.prefixes() method.
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
