[Framework] assign-models.js reads from symlinked .opencode/agents instead of canonical .agents/agents #96

Problem

utils/assign-models.js line 5 sets AGENTS_DIR = path.resolve(__dirname, "..", ".opencode", "agents"). This works only when .opencode/agents is a real resolved symlink to .agents/agents. Anywhere that symlink is inert (see the Windows symlink issue), this script silently finds 0 agent files instead of erroring — compounding that bug for anyone trying to fix model assignments on an affected machine.

Fix

Point AGENTS_DIR directly at the canonical source of truth: .agents/agents, not the .opencode symlink indirection.

Acceptance criteria

• utils/assign-models.js reads/writes .agents/agents/*.md directly
• Script works correctly regardless of .opencode/agents symlink state