[core-shrink] flows: move the builder tool belt into tinyflows-copilot #7396

Parent: #7390

Context

flows/builder_tools/ (3.5k lines plus about 2.5k test lines) is the authoring tool belt: edit, revise, validate, dry run, persist and reads. tinyflows-copilot is the right home.

Scope

• Move builder_tools/* to tinyflows-copilot. Exceptions: catalog_search.rs and connection_reads.rs are bound to Composio, so they stay as host tools, or become host-supplied implementations of a copilot trait.
• dry_run.rs already uses tinyflows mocks: move it.
• bus/dedup_commit.rs (the dedup node's exactly-once contract) → tinyflows. bus/{trigger, run_digest, owner}.rs stay.
• discovery_tools.rs: the SuggestWorkflowsTool type moves, its registration stays.
• Move parameters/*.json (3 tool schemas) with their tools.
• Move builder_tools_*_tests.rs.

Acceptance criteria

• Tool names and JSON schemas are byte-identical. They are recorded in session transcripts and must keep matching. Add a schema snapshot test.
• flows/builder_tools/ is gone, or only registers the copilot tools with host implementations.

Verification

pnpm rust:layout, cargo check (root + crates/openhuman-app manifest), pnpm test:rust (affected filters), node scripts/ci/check-feature-forwarding.mjs, scripts/e2e-core.sh against the compose stack. Upstream submodule PR lands first, then the gitlink bump here; every behaviour change ships with a regression test.