chore(deps): zod 3→4 major

[terraboops]

Bumps zod from 3.x to ^4.4.3 in all three packages that declare it: @autonav/core, @autonav/communication-layer, @autonav/pack-server.

Changes

• zod ^4.4.3 in the 3 package.json files.
• Coupled: added a scoped root overrides forcing @anthropic-ai/claude-agent-sdk onto zod ^4.4.3 (it declares zod: ^4.0.0 but npm had left it on the invalid hoisted 3.25.76). This unifies on a single hoisted zod 4.4.3 and resolves a dual-instance type clash in the SDK's tool() typing. mintlify's nested zod 3 (via nono-ts) is left untouched.
• zod 4 API migrations:
  • z.record(z.unknown()) → z.record(z.string(), z.unknown()) (record now requires key + value schema).
  • result.error.errors → result.error.issues (ZodError shape).
  • .refine(check, (val) => ({ message })) → .refine(check, { error: (iss) => ... }) (function-message form removed).
  • Schema introspection in config-describe.ts rewritten for zod 4 internals: _def.typeName → _zod.def.type (lowercase discriminators), enum values→entries, array type→element, default defaultValue now a value not a factory, descriptions via .description getter.

Test

Commands run from repo root:

• npm run typecheck (runs npm run build + per-workspace tsc --noEmit) → pass
• npm test → 157 pass / 0 fail (autonav 112 pass, communication-layer 45 pass; 22 skipped). pack-server has no test script.

Note: one smoke test (init.smoke.test.ts) can flake under parallel execution due to a shared ~/.claude/skills symlink collision — pre-existing and unrelated to zod; passes in isolation and on rerun.