all: apply godoc [Name] link conventions across comments

Every Go-identifier reference in // and /* */ comments now uses
godoc's [Name] linking syntax so pkg.go.dev and `go doc` render
them as clickable cross-references. No behaviour change.

Pattern applied across the tree:
  In-package         [Foo], [Foo.Bar]
  Cross-package      [pkg.Foo], [pkg.Foo.Bar]
  Stdlib             [netip.Prefix], [errors.Is], [context.Context]
  Tailscale          [tailcfg.MapResponse], [tailcfg.Node.CapMap],
                     [tailcfg.NodeAttrSuggestExitNode]

Skip rules:
  - File:line refs left as plain text
  - HuJSON wire keys inside backtick raw strings untouched
  - ACL/policy syntax tokens (tag:foo, autogroup:self, ...) not Go
    symbols, left as plain text
  - JSON/OIDC wire keys, gorm tags, RFC IPv6 placeholders, markdown
    link tags, decorative dividers — all left as-is

cmd/hi/docker.go

@@ -830,7 +830,7 @@ func extractContainerLogs(ctx context.Context, cli *client.Client, containerID,
 
 // extractContainerFiles extracts database file and directories from headscale containers.
 // Note: The actual file extraction is now handled by the integration tests themselves
-// via SaveProfile, SaveMapResponses, and SaveDatabase functions in hsic.go.
+// via [SaveProfile], [SaveMapResponses], and [SaveDatabase] functions in hsic.go.
 func extractContainerFiles(ctx context.Context, cli *client.Client, containerID, containerName, logsDir string, verbose bool) error {
 	// Files are now extracted directly by the integration tests
 	// This function is kept for potential future use or other file types