[TKN-716] Group Dependabot updates by package category

[calintje]

Summary

Configures Dependabot with dependency grouping to reduce PR volume while maintaining safety for breaking changes. Groups 729 dependencies across npm and Cargo ecosystems based on analysis of lockfiles.

Process

To determine optimal grouping strategies, I ran analysis scripts against the repository's lockfiles:

1. npm/yarn analysis: Parsed yarn.lock to identify scoped packages (@scope/package patterns) and count their prevalence
2. Root Cargo analysis: Analyzed Cargo.lock to identify common prefixes (prefix-* patterns)
3. SDK Cargo analysis: Aggregated analysis across 7 Cargo.lock files in subdirectories:
   • rust-sdk/{client,core,macros,tx-sender,whirlpool}
   • ts-sdk/core
   • examples/rust-sdk/whirlpool_repositioning_bot

Strategy

### Grouping Rules

• Group together: Minor and patch updates for related packages
• Keep separate: Major version updates (breaking changes requiring review)

---

Dependency Groups

Total: 729 packages across 23 groups

1. JavaScript/npm Dependencies (Root yarn.lock)

Group Name	Package Count
docusaurus	26
solana-v1	4
solana-v2-core	39
solana-v2-programs	6
typescript-types	55
build-tools	163
testing-tools	8
monorepo-tools	11
linting-tools	18
release-tools	19
codegen-tools	14
docs-tooling	94
nextjs	11
TOTAL	468

2. Cargo - Root Program (Cargo.lock, Solana v1.17)

Group Name	Package Count
solana-ecosystem	23
anchor-framework	12
serialization	10
cryptography	16
wasm-tooling	5
TOTAL	66

3. Cargo - SDK Subdirectories (Multiple Cargo.lock files, Solana v2.x)

Group Name	Package Count
solana-sdk	130
serialization	16
cryptography	18
wasm-tooling	7
async-runtime	24
TOTAL	195

[wjthieme]

Think you can omit the update-types everywhere. Otherwise LGTM