feat: refactor model selection to use developer tiers

- Replaced raw model aliases with developer tiers (junior, medior, senior, qa) in dispatch and model selection logic.
- Updated `dispatchTask` to resolve models based on tiers and plugin configuration.
- Modified `selectModel` to return tier names instead of model aliases based on task description.
- Implemented migration logic for transitioning from old model aliases to new tier names in worker state.
- Added setup logic for agent creation and model configuration in `setup.ts`.
- Created shared templates for workspace files and instructions for DEV/QA workers.
- Enhanced project registration to scaffold role files based on developer tiers.
- Updated task management tools to reflect changes in model selection and tier assignment.
- Introduced a new `devclaw_setup` tool for agent-driven setup and configuration.
- Updated plugin configuration schema to support model mapping per developer tier.

lib/tiers.ts

@@ -0,0 +1,66 @@
+/**
+ * Developer tier definitions and model resolution.
+ *
+ * Tasks are assigned to developer tiers (junior, medior, senior, qa)
+ * instead of raw model names. Each tier maps to a configurable LLM model.
+ */
+
+export const DEV_TIERS = ["junior", "medior", "senior"] as const;
+export const QA_TIERS = ["qa"] as const;
+export const ALL_TIERS = [...DEV_TIERS, ...QA_TIERS] as const;
+
+export type DevTier = (typeof DEV_TIERS)[number];
+export type QaTier = (typeof QA_TIERS)[number];
+export type Tier = (typeof ALL_TIERS)[number];
+
+export const DEFAULT_MODELS: Record<Tier, string> = {
+  junior: "anthropic/claude-haiku-4-5",
+  medior: "anthropic/claude-sonnet-4-5",
+  senior: "anthropic/claude-opus-4-5",
+  qa: "anthropic/claude-sonnet-4-5",
+};
+
+/** Emoji used in announcements per tier. */
+export const TIER_EMOJI: Record<Tier, string> = {
+  junior: "⚡",
+  medior: "🔧",
+  senior: "🧠",
+  qa: "🔍",
+};
+
+/** Check if a string is a valid tier name. */
+export function isTier(value: string): value is Tier {
+  return (ALL_TIERS as readonly string[]).includes(value);
+}
+
+/** Check if a string is a valid dev tier name. */
+export function isDevTier(value: string): value is DevTier {
+  return (DEV_TIERS as readonly string[]).includes(value);
+}
+
+/**
+ * Resolve a tier name to a full model ID.
+ *
+ * Resolution order:
+ * 1. Plugin config `models` map (user overrides)
+ * 2. DEFAULT_MODELS (hardcoded defaults)
+ * 3. Treat input as raw model ID (passthrough for non-tier values)
+ */
+export function resolveModel(
+  tier: string,
+  pluginConfig?: Record<string, unknown>,
+): string {
+  const models = (pluginConfig as { models?: Record<string, string> })?.models;
+  return models?.[tier] ?? DEFAULT_MODELS[tier as Tier] ?? tier;
+}
+
+/**
+ * Migration map from old model-alias session keys to tier names.
+ * Used by migrateWorkerState() in projects.ts.
+ */
+export const TIER_MIGRATION: Record<string, string> = {
+  haiku: "junior",
+  sonnet: "medior",
+  opus: "senior",
+  grok: "qa",
+};