chore: switch @lead/@ops from Anthropic to xAI grok-4.5

Removes the last Anthropic-model usage from the agent registry.
XAI_API_KEY was already provisioned as an org secret; wire it into
the run-agent step and update every doc/comment that referenced
ANTHROPIC_API_KEY or claude-opus-4-8.

.gitea/workflows/scripts/agents.json

@@ -25,7 +25,7 @@
     "desc": "Senior dev — complex, multi-file implementation (GLM-5.2 via Ollama Cloud, text-only)."
   },
   "lead": {
-    "model": "anthropic/claude-opus-4-8",
+    "model": "xai/grok-4.5",
     "vision": true,
     "mode": "pr",
     "skills": [
@@ -43,7 +43,7 @@
     "desc": "QA / reviewer — reviews PRs: reads the diff, drives a headless browser (Playwright) to verify behavior, posts specific recommendations on the PR and the pass/fail verdict on the issue. Never edits code, never merges."
   },
   "ops": {
-    "model": "anthropic/claude-opus-4-8",
+    "model": "xai/grok-4.5",
     "vision": false,
     "mode": "comment",
     "skills": [

.gitea/workflows/scripts/build-activity-log.sh

@@ -38,7 +38,7 @@ COST=${COST:-0}; INP=${INP:-0}; OUT=${OUT:-0}; CR=${CR:-0}; CW=${CW:-0}; RE=${RE
 IN_TOTAL=$(( INP + CR + CW ))                          # total input context processed
 # Cost label: ollama / ollama-cloud models are SUBSCRIPTION-billed (GPU-time against the plan, no
 # $/token price exists), so a "$0.0000" there would be misleading — label it a subscription instead.
-# Metered providers (anthropic/…) get the real dollar cost opencode computed.
+# Metered providers (xai/…) get the real dollar cost opencode computed.
 case "${MODEL:-}" in
   ollama*|*"/ollama"*) COSTF="subscription" ;;
   *) COSTF=$(awk -v c="$COST" 'BEGIN{printf "$%.4f", c+0}') ;;

.gitea/workflows/scripts/install-opencode.sh

@@ -42,7 +42,7 @@ PERM=$(jq -nc --argjson s "$SKILLS" '
 # The provider `models:` maps are DERIVED from agents.json (the single source of truth, shared with
 # route.sh) so every model an agent is routed to is always declared in the provider config.
 # `ollama-cloud/` prefix models go to the cloud provider; `ollama/` prefix models go to the local
-# provider. Built-in providers (e.g. `anthropic/claude-opus-4-8` for @lead) are not derived here.
+# provider. Built-in providers (e.g. `xai/grok-4.5` for @lead/@ops) are not derived here.
 # See issue #31.
 AGENTS_JSON="${SCRIPTS:-$(dirname -- "$0")}/agents.json"
 CLOUD_MODELS=$(jq -r '[.[] | .model | select(startswith("ollama-cloud/")) | sub("^ollama-cloud/";"")] | map({(.):{}}) | add // {}' "$AGENTS_JSON")

.gitea/workflows/scripts/run-agent.sh

@@ -3,7 +3,7 @@
 # plain-text reply (/tmp/agent_out.md) plus the raw event stream (/tmp/events.jsonl).
 #
 # Required env (provided by the workflow step):
-#   ANTHROPIC_API_KEY SELF_TOKEN NAME MODEL VISION MODE HAS_IMAGES BRANCH AUTOPILOT NUM TITLE
+#   XAI_API_KEY SELF_TOKEN NAME MODEL VISION MODE HAS_IMAGES BRANCH AUTOPILOT NUM TITLE
 #   IBODY CMT
 #   FILES   (the opencode -f image flags, from the imgs step output)
 #   AUTOPILOT is 'true' when the issue carries the `autopilot` label (label-gated autopilot mode).

.gitea/workflows/scripts/skill-gitea-admin.sh

@@ -107,7 +107,7 @@ curl -sS -X POST -H "Authorization: token $SELF_TOKEN" "$API/orgs/{org}/labels"
 3. Commit the standard caller so it gets the agents — `PUT /repos/{owner}/{repo}/contents/.gitea/workflows/ai-agent.yml`
    with base64 `content`, `message`, `branch:"main"` (copy the exact caller from the `agents` repo README).
 4. Add the agent bot users as collaborators: `PUT /repos/{owner}/{repo}/collaborators/{username}` (`{"permission":"write"}`).
-5. Ensure the repo can run agents — the org must hold the runtime secrets (ANTHROPIC_API_KEY, SELF_TOKEN,
+5. Ensure the repo can run agents — the org must hold the runtime secrets (XAI_API_KEY, SELF_TOKEN,
    TOKEN_* , OLLAMA_URL, OLLAMA_CLOUD_API_KEY); set any missing via the secrets calls above.
 
 ## Packages / container registry