fix: chore: create formula label in Codeberg + add more formula templates (#22)

- Add formulas/upgrade-dependency.toml: multi-ecosystem (npm/cargo/forge) dependency upgrade
  with steps for checking changelog, upgrading, applying breaking changes, and running tests
- Add formulas/add-rpc-method.toml: JSON-RPC method addition with steps for reading
  existing patterns, implementing handler, registering, writing tests, and running tests
- Document `formula` label in BOOTSTRAP.md optional labels table

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

formulas/upgrade-dependency.toml

@@ -0,0 +1,78 @@
+# formulas/upgrade-dependency.toml — Upgrade a package dependency
+
+name        = "upgrade-dependency"
+description = "Upgrade {{package}} from {{from_version}} to {{to_version}}"
+version     = 1
+
+[vars.package]
+description = "Package name to upgrade (e.g. viem, serde, forge-std)"
+required    = true
+
+[vars.ecosystem]
+description = "Package ecosystem: npm, cargo, or forge"
+required    = true
+
+[vars.from_version]
+description = "Current version (e.g. 1.2.3) — used for changelog lookup"
+required    = false
+default     = "current"
+
+[vars.to_version]
+description = "Target version (e.g. 2.0.0) — leave blank for latest"
+required    = false
+default     = "latest"
+
+[[steps]]
+id          = "check-current"
+title       = "Check current {{package}} version and changelog"
+description = """
+Identify the installed version of {{package}} in the lockfile or manifest.
+Look up the changelog or release notes between {{from_version}} and {{to_version}}.
+Note any breaking changes, deprecations, or migration steps required.
+"""
+
+[[steps]]
+id          = "upgrade"
+title       = "Run upgrade for {{ecosystem}}"
+description = """
+Run the appropriate upgrade command for ecosystem={{ecosystem}}:
+
+- npm:   npm install {{package}}@{{to_version}} (or @latest)
+         Then: npm install  (to sync lockfile)
+- cargo: cargo update -p {{package}} [--precise {{to_version}}]
+         Or bump version in Cargo.toml, then: cargo build
+- forge: Update version in foundry.toml or gitmodules, then:
+         forge install {{package}}  (or forge update {{package}})
+
+Confirm the lockfile / manifest now reflects {{to_version}}.
+"""
+needs       = ["check-current"]
+
+[[steps]]
+id          = "fix-breaking-changes"
+title       = "Apply migration steps for breaking changes"
+description = """
+Based on the changelog reviewed in check-current, apply any required changes:
+- Rename renamed APIs or types
+- Update import paths if they moved
+- Adjust call sites for signature changes
+- Remove usage of deprecated symbols
+
+If no breaking changes were noted, verify a quick build still passes.
+"""
+needs       = ["upgrade"]
+
+[[steps]]
+id          = "run-tests"
+title       = "Run tests and verify"
+description = """
+Run the full test suite appropriate for ecosystem={{ecosystem}}:
+
+- npm:   npm test (or the project's test script)
+- cargo: cargo test
+- forge: forge test
+
+Confirm all tests pass. Fix any compilation errors or test failures introduced
+by the upgrade before declaring this done.
+"""
+needs       = ["fix-breaking-changes"]