test: add YearnGaugeStrategy Echidna test

[penandlim]

Describe your changes

Currently echidna need to export the RPC URL and block via env variable

Checklist before requesting a review

• Title follows conventional commits style
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works
• Newly added functions follow Check-effects-interaction
• Gas usage has been minimized (ex. Storage variable access is minimized)

[github-actions]

Slither report

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Summary

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.66%. Comparing base (b3ac9a2) to head (a036c29).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #219   +/-   ##
=======================================
  Coverage   98.66%   98.66%           
=======================================
  Files          19       19           
  Lines         824      824           
  Branches      162      162           
=======================================
  Hits          813      813           
  Partials       11       11           

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[github-actions]

Changes to gas cost

Generated at commit: 6da47d3a8a4c9ec1a2b21f1391c0af13b438fcba, compared to commit: 67328aed772f7a07185a175e8186e38ea3d49dc1

🧾 Summary (10% most significant diffs)

Contract	Method	Avg (+/-)	%
YSDRewardsGauge	deposit redeem	+8,083 ❌ +9,844 ❌	+3.74% +7.58%

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Full diff report 👇

Contract	Deployment Cost (+/-)	Method	Min (+/-)	%	Avg (+/-)	%	Median (+/-)	%	Max (+/-)	%	# Calls (+/-)
YSDRewardsGauge	3,892,863 (-2,400)	addReward deposit depositRewardToken redeem	47,622 (+107) 9,279 (0) 144,975 (+107) 8,643 (0)	+0.23% 0.00% +0.07% 0.00%	58,572 (+107) 223,969 (+8,083) 147,145 (+107) 139,748 (+9,844)	+0.18% +3.74% +0.07% +7.58%	58,572 (+107) 161,760 (0) 147,145 (+107) 150,158 (+19,688)	+0.18% 0.00% +0.07% +15.09%	69,522 (+107) 483,761 (+26) 149,316 (+107) 250,034 (0)	+0.15% +0.01% +0.07% 0.00%	42 (0) 7 (0) 2 (0) 4 (0)
GaugeRewardReceiver	1,420,474 (0)	harvest	5,816 (0)	0.00%	245,313 (+5,559)	+2.32%	273,136 (0)	0.00%	406,895 (0)	0.00%	18 (0)
YearnStakingDelegate	3,055,815 (+36)	harvest	24,010 (0)	0.00%	235,894 (+4,715)	+2.04%	298,278 (0)	0.00%	377,863 (0)	0.00%	17 (0)
ERC20RewardsGauge	3,566,734 (-2,400)	addReward depositRewardToken setRewardDistributor	3,053 (0) 10,063 (0) 5,138 (0)	0.00% 0.00% 0.00%	61,053 (+98) 151,396 (+96) 5,737 (+27)	+0.16% +0.06% +0.47%	69,529 (+107) 147,613 (+107) 5,190 (0)	+0.15% +0.07% 0.00%	73,529 (+107) 195,697 (+107) 7,431 (+107)	+0.15% +0.05% +1.46%	66 (0) 19 (0) 4 (0)
RewardForwarder	1,216,659 (-1,944)	forwardRewardToken initialize setTreasury setTreasuryBps	5,854 (0) 23,333 (0) 8,990 (+86) 9,224 (0)	0.00% 0.00% +0.97% 0.00%	85,278 (+46) 158,904 (+90) 20,620 (+43) 35,902 (+60)	+0.05% +0.06% +0.21% +0.17%	55,914 (0) 161,563 (+92) 20,620 (+43) 32,555 (+60)	0.00% +0.06% +0.21% +0.18%	165,424 (+107) 161,563 (+92) 32,251 (0) 69,274 (+119)	+0.06% +0.06% 0.00% +0.17%	7 (0) 52 (0) 2 (0) 4 (0)
CoveToken	2,675,051 (0)	addAllowedReceiver mint removeAllowedReceiver removeAllowedSender transfer	26,510 (0) 26,558 (-216) 31,019 (-216) 31,097 (-84) 28,652 (-180)	0.00% -0.81% -0.69% -0.27% -0.62%	51,510 (-27) 49,425 (-43) 38,686 (-72) 38,680 (-28) 46,584 (-49)	-0.05% -0.09% -0.19% -0.07% -0.11%	55,335 (0) 53,952 (0) 31,235 (0) 31,181 (0) 52,208 (-12)	0.00% 0.00% 0.00% 0.00% -0.02%	55,335 (0) 63,400 (-36) 53,805 (0) 53,762 (0) 55,946 (0)	0.00% -0.06% 0.00% 0.00% 0.00%	8 (0) 7 (0) 3 (0) 3 (0) 14 (0)
YearnGaugeStrategy	2,001,549 (0)	approve deposit redeem	49,322 (-36) 30,677 (0) 301,707 (-72)	-0.07% 0.00% -0.02%	49,340 (-36) 292,047 (-4) 308,545 (-12)	-0.07% -0.00% -0.00%	49,340 (-36) 373,477 (0) 306,465 (0)	-0.07% 0.00% 0.00%	49,358 (-36) 452,829 (0) 319,544 (+24)	-0.07% 0.00% +0.01%	2 (0) 33 (0) 4 (0)
MiniChefV3	3,124,141 (0)	commitReward deposit rescue	76,638 (-24) 24,361 (0) 34,796 (-48)	-0.03% 0.00% -0.14%	76,709 (-2) 109,290 (-11) 49,742 (-24)	-0.00% -0.01% -0.05%	76,698 (0) 121,138 (0) 54,479 (0)	0.00% 0.00% 0.00%	76,806 (0) 124,261 (0) 67,842 (0)	0.00% 0.00% 0.00%	9 (0) 15 (0) 7 (0)
CoveYearnGaugeFactory	2,596,142 (0)	deployCoveGauges	24,068 (0)	0.00%	1,902,348 (+442)	+0.02%	2,235,006 (+505)	+0.02%	2,235,006 (+505)	+0.02%	24 (0)
DYFIRedeemer	2,139,607 (0)	massRedeem	30,408 (0)	0.00%	401,893 (-2)	-0.00%	428,864 (0)	0.00%	675,052 (0)	0.00%	15 (0)