[ftgonc]

Stacked on #13 ("follow local values when building the resource graph"): this branch contains its two commits. Only the last commit, Draw module calls as nodes in oxid graph, is new here. I'll rebase once #13 is merged.

Summary

Modules are opaque to the resource graph, so oxid graph leaves out every module call. Configurations built mostly from modules render as a handful of disconnected data sources, and resources that consume module outputs have no incoming edges.

This adds module calls to the oxid graph output without expanding them:

• Collect module.<name> references, both in expressions and in ${…} interpolations inside nested blocks. In the execution graph they still don't resolve to any node, so plan and apply are unchanged
• New to_dot_with_modules, used by oxid graph: each module call becomes a node (shape=component) labelled with its name and a short form of its source (git::https://host/repo.git//database?ref=v1 → database; local and registry sources are shown as-is)
• A module is linked from the resources, data sources and modules its arguments (including count, for_each and depends_on) reference, and to the resources, data sources, outputs and modules that use its outputs. Both directions follow locals, using the resolution from fix: follow local values when building the resource graph #13
• Factor a resource's reference collection into resource_references, shared by the DAG builder and the DOT output

Out of scope

• Expanding module contents (fetching sources, planning their resources). Module internals still don't appear, and plan/apply still treat modules as opaque
• Module nodes in blast-radius or oxid graph -T module

Test plan

• New tests in tests/resource_graph_test.rs: module node label and shape with a git source and a local source; edges data source → module (through a local), module → module (through a for over module instances), module → resource (via count and attributes through a local), module → output; to_dot (plan/apply graph) gains no module nodes; config without modules renders the same as to_dot
• Full test suite passes (133 tests, 0 failures)
• cargo fmt --all -- --check clean
• cargo clippy --all-targets -- -D warnings: no new findings. Current stable clippy reports 33 pre-existing double_must_use errors in src/state/backend.rs on main as well, untouched here
• Manually on six real configurations: every module call now appears and is connected. For example, in a database config (12 nodes, 6 edges before) the database module now appears, linked from the network lookups it uses and to the five provisioning resources that consume its outputs (13 nodes, 14 edges); a config made only of modules went from 2 nodes and no edges to 5 nodes and 3 edges

[chaitanya-sistla]

@ftgonc approved workflows

[chaitanya-sistla]

@ftgonc most of the PRs security and clippy failed. Could you test this again?

[chaitanya-sistla]

@ftgonc checking in here again.