docs: sync routing-strategy count to 18 across README + AGENTS.md

[chirag127]

Problem

Source of truth src/shared/constants/routingStrategies.ts:1-20 lists 18 entries in ROUTING_STRATEGY_VALUES (priority, weighted, round-robin, context-relay, fill-first, p2c, random, least-used, cost-optimized, reset-aware, reset-window, headroom, strict-random, auto, lkgp, context-optimized, fusion, pipeline). docs/routing/AUTO-COMBO.md:177 and CLAUDE.md:75 correctly say 18, but 5 doc lines still advertise 17:

• README.md:33 — shields.io badge 17-Routing_Strategies
• README.md:878 — tagline 17 strategies · task-aware smart routing …
• AGENTS.md:542 — landing table Auto-Combo (12-factor, 17 strategies)
• docs/i18n/zh-CN/README.md:33 — same badge
• docs/i18n/zh-TW/README.md:33 — same badge

Onboarding devs see conflicting counts.

Fix

Replace 17 with 18 on the 5 lines above (badge alt text, badge URL, tagline, table entry). No code touch.

Testing

Docs-only diff. Verified count against ROUTING_STRATEGY_VALUES array in src/shared/constants/routingStrategies.ts (18 entries). Rendered markdown checked: badge URL still resolves via shields.io.

Alternatives considered

Auto-generate the count from ROUTING_STRATEGY_VALUES at build-time — overkill for a rarely-changing constant; deferred until strategies churn again.

Thanks for the excellent OmniRoute!