fix: resolve three open bugs (#2836, #2858, #2873)

- fix(context-limit): check modelContextLimitsCache for all Anthropic
  models, not just GA-model set; user config/cache wins over 200K default
  (fixes #2836)

- fix(agent-key-remapper): preserve config key aliases alongside display
  names so `opencode run --agent sisyphus` resolves correctly
  (fixes #2858)

- fix(tool-config): respect host permission.skill=deny by disabling
  skill/skill_mcp tools when host denies them (fixes #2873)

- test: update context-limit and agent-key-remapper tests to match new
  behavior

src/plugin-handlers/tool-config-handler.ts

@@ -29,6 +29,9 @@ export function applyToolConfig(params: {
     ? { todowrite: "deny", todoread: "deny" }
     : {}
 
+  const existingPermission = params.config.permission as Record<string, unknown> | undefined;
+  const skillDeniedByHost = existingPermission?.skill === "deny";
+
   params.config.tools = {
     ...(params.config.tools as Record<string, unknown>),
     "grep_app_*": false,
@@ -40,6 +43,9 @@ export function applyToolConfig(params: {
     ...(params.pluginConfig.experimental?.task_system
       ? { todowrite: false, todoread: false }
       : {}),
+    ...(skillDeniedByHost
+      ? { skill: false, skill_mcp: false }
+      : {}),
   };
 
   const isCliRunMode = process.env.OPENCODE_CLI_RUN_MODE === "true";