feat(morpho): group V2 pending alerts and improve cap formatting

[spalen0]

What

Two improvements to the Morpho VaultV2 governance monitor, driven by these example alerts:

⚠️ ⏳ V2 Steakhouse Prime USDC on KATANA
📥 Submitted: increaseRelativeCap(collateral token 0x9893…19a7 → cap 1000000000000000000)
...
⚠️ ⏳ V2 Steakhouse Prime USDC on KATANA
📥 Submitted: increaseRelativeCap(market weETH/vbUSDC → cap 1000.00B vbUSDC)

1. Group per-vault pending alerts into one message

A batched multicall submit previously fired one Telegram message per operation. _diff_pending now collects all newly-submitted timelocked operations for a vault and sends a single grouped alert. When every op shares the same execution time and tx (the multicall case), those are shown once in the footer; otherwise they render per-op. Single-op alerts keep their original format.

2. Better cap-setter rendering

• Collateral tokens link by symbol — e.g. collateral token [weETH](https://katanascan.com/address/0x9893…19a7), via a new assetByAddress fetch in _shared.py, falling back to the bare-address link when the symbol can't be resolved.
• Relative caps render as percentages — increaseRelativeCap values are WAD ratios (1e18 = 100%), not token amounts. Both example alerts are actually 1e18 = 100%; the market one was mis-rendered as 1000.00B vbUSDC. Now both the collateral-token and market paths show cap 100.0000%. Absolute caps keep token-amount formatting.

Result:

increaseRelativeCap(collateral token [weETH](katanascan/…) → cap 100.0000%)
increaseRelativeCap(market [weETH/vbUSDC](morpho/…) → cap 100.0000%)

Notes

• Absolute caps on a collateral-token id still show the raw value: an absolute cap is denominated in the vault's underlying asset (not the collateral token), which the decoder doesn't have in scope. Not present in the example alerts.
• fetch_asset_metadata is an uncached GraphQL call per collateral-token cap during rendering — consistent with the existing fetch_market_metadata pattern.

Testing

• Added tests: grouped multi-op alert (shared footer), single-op format, collateral-token symbol link + relative-cap percentage, symbol-unresolved fallback, and the market relative-cap percentage path.
• uv run pytest tests/ → 671 passed, 4 skipped. ruff check/format clean.

🤖 Generated with Claude Code