Fix: variant field causes 'Invalid API parameter' on GLM provider

The variant:high/variant:max fields injected by the installer are
provider-specific. The ZAI/GLM-5.2 provider does not support the
OpenCode variant parameter — every subagent spawn fails with
'Invalid API parameter, please check the documentation.'

Root cause: OpenCode passes the agent's variant field to the provider
as a model option. Providers that don't recognize the variant name
reject the entire API call. The main build agent works because its
model comes from opencode.json (no variant). Only subagents with
variant: in their frontmatter fail.

Fix:
- Stripped variant from all 49 agents in ocg-test and stillcurrent
- Added warning in install.sh when --variant-* flags are provided
- Documented in lib/models.sh that variant is provider-specific

The model field (zai-coding-plan/glm-5.2) is retained on all agents —
only the variant is removed. Users whose provider supports variants
can add them manually to agent frontmatter.

Author: Cipher-85

.opencode/install.sh

@@ -133,6 +133,13 @@ fi
 # ── Validate models ──────────────────────────────────────────────
 printf '\n── Validating models ──────────────────────────────────────\n'
 
+# Warn about variants if provided
+if [ -n "$opus_variant$sonnet_variant$haiku_variant" ]; then
+  printf '  ⚠  Variants are provider-specific. If your provider does not support\n' >&2
+  printf '     the variant parameter, subagent tasks will fail with "Invalid API\n' >&2
+  printf '     parameter". If this happens, re-run without --variant-* flags.\n\n' >&2
+fi
+
 validation_failed=0
 for tier in opus sonnet haiku; do
   eval "model=\"\${${tier}_model:-}\""

.opencode/lib/models.sh

@@ -60,8 +60,10 @@ else:
 " 2>/dev/null
 }
 
-# Inject or replace model: and variant: in an agent file's frontmatter
+# Inject or replace model: in an agent file's frontmatter
 # Usage: ccgs_inject_model <agent_file> <model_id> [variant]
+# Note: variant is provider-specific and may cause "Invalid API parameter"
+# errors if the provider doesn't support it. Leave empty to omit.
 ccgs_inject_model() {
   local file="$1" model_id="$2" variant="${3:-}"
   python3 -c "