docs: surface INSTALL entrypoint / 在 README 與 HANDOFF 補 INSTALL 入口

HANDOFF.md

@@ -37,14 +37,15 @@ This is not yet a clean cross-agent installable package. It is a successful PoC
 
 Read these files first:
 
-1. `README.md`
-2. `telegram-v1-design.md`
-3. `telegram-openclaw-poc-plan.md`
-4. `reports/telegram-openclaw-poc-success.md`
-5. `reports/openclaw-patch-inventory.md`
-6. `reports/openclaw-patch-mapping-matrix.md`
-7. `reports/next-phase-implementation-plan.md`
-8. `reports/agent-consumable-minimum.md`
+1. `INSTALL.md`
+2. `README.md`
+3. `telegram-v1-design.md`
+4. `telegram-openclaw-poc-plan.md`
+5. `reports/telegram-openclaw-poc-success.md`
+6. `reports/openclaw-patch-inventory.md`
+7. `reports/openclaw-patch-mapping-matrix.md`
+8. `reports/next-phase-implementation-plan.md`
+9. `reports/agent-consumable-minimum.md`
 
 ## Fastest operational entrypoints