feat(ccip): cap LINK funding to deployer balance per chain; fix Arbitrum gas

- parse_link_tags: add --cap-to-deployer for fund-ccip-bridges-with-link.sh
- fund-ccip: min(target, balance//bridges) per chain; reuse one wei for both
  bridges under cap so post-transfer balance does not undershoot the second send
- Arbitrum: append legacy --gas-price from RPC (3x) with floor to clear base fee

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/lib/deployment/prompts.sh

@@ -171,8 +171,11 @@ parse_lockbox_tag() {
   PARSE_LOCKBOX_REMAINING=("${args[@]}")
 }
 
-# Parse --link <amount> (ETH or wei if --link-wei), --dry-run. Sets LINK_AMOUNT_WEI, DRY_RUN.
+# Parse --link <amount> (ETH or wei if --link-wei), --dry-run, --cap-to-deployer.
+# Sets LINK_AMOUNT_WEI, DRY_RUN, CAP_LINK_TO_DEPLOYER_BALANCE (0/1).
 # Default LINK_AMOUNT_WEI 10e18 (10 LINK) when unset. Unconsumed in PARSE_LINK_TAGS_REMAINING.
+# --cap-to-deployer: callers (e.g. fund-ccip-bridges-with-link.sh) cap each bridge transfer to
+# min(LINK_AMOUNT_WEI, deployer_LINK_balance // bridges_on_that_chain).
 link_to_wei() {
   local val="${1:-0}"
   if [[ -z "$val" || "$val" == "0" ]]; then echo "0"; return; fi
@@ -189,6 +192,7 @@ link_to_wei() {
 parse_link_tags() {
   export LINK_AMOUNT_WEI="${LINK_AMOUNT_WEI:-10000000000000000000}"
   export DRY_RUN="${DRY_RUN:-0}"
+  export CAP_LINK_TO_DEPLOYER_BALANCE="${CAP_LINK_TO_DEPLOYER_BALANCE:-0}"
   local args=()
   local i=0
   local argv=("$@")
@@ -201,6 +205,7 @@ parse_link_tags() {
       --link-wei)
         [[ $((i+1)) -lt ${#argv[@]} ]] && LINK_AMOUNT_WEI="${argv[$((i+1))]}"
         i=$((i+2)); ;;
+      --cap-to-deployer) CAP_LINK_TO_DEPLOYER_BALANCE=1; i=$((i+1)); ;;
       --dry-run) DRY_RUN=1; i=$((i+1)); ;;
       *) args+=("$a"); i=$((i+1)); ;;
     esac