fix(comms-mcp): add GmailResource + CalendarResource enums to Zig FFI (standards#151) (#124)

Class C ABI gap. `GmailResource` (4 variants) + `CalendarResource` (3
variants) were Idris2-only.

`iseriser abi-verify` → exit 0 (4 enums, 6 transitions); `zig build
test` → 21/21 green.

Closes hyperpolymath/standards#151
Refs hyperpolymath/standards#92, #89

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

cartridges/comms-mcp/ffi/comms_ffi.zig

@@ -26,6 +26,24 @@ pub const CommsProvider = enum(c_int) {
     custom = 99,
 };
 
+/// Gmail resource types — mirrors `CommsMcp.SafeComms.GmailResource`
+/// + `gmResourceToInt` encoding. Declared here so `iseriser abi-verify`
+/// can structurally check the encoding against the Idris2 source.
+pub const GmailResource = enum(c_int) {
+    gm_message = 1,
+    gm_thread = 2,
+    gm_label = 3,
+    gm_draft = 4,
+};
+
+/// Google Calendar resource types — mirrors
+/// `CommsMcp.SafeComms.CalendarResource` + `calResourceToInt` encoding.
+pub const CalendarResource = enum(c_int) {
+    cal_event = 1,
+    cal_calendar = 2,
+    cal_free_busy = 3,
+};
+
 // ═══════════════════════════════════════════════════════════════════════
 // Session State Machine
 // ═══════════════════════════════════════════════════════════════════════