Add Range42 stack previews and improve runtime reliability

[pparage]

The backend can now generate a reviewable Range42 stack for the project canvas. The UI receives the planned machines, network and project files before the user adds the stack. Previewing a stack does not create or change Proxmox resources.

What changes:

• Adds stack previews for the core and full profiles, using the platform generator installed by the operator. Invalid input and an unavailable generator return clear errors.
• Exposes stack profiles and setup fields to the deployment form, and checks required values before execution. Native deployments keep publishing progress events when switching to their selected CLI context.
• Enables additional VM interfaces, resource settings and disk growth only for a verified runtime that supports them. Preflight blocks templates with unreadable network settings or interfaces missing from the requested topology.
• Prevents false snapshot configuration differences caused by Proxmox returning a masked cloud-init password in one response and its hash in another.
• Reduces unnecessary work in idle event streams and releases watchers when a client disconnects.
• Checks reviewed VM identities using bounded parallel reads before network or firewall changes, retaining the ownership checks while reducing sequential API calls.

Companion UI: range42/range42-deployer-ui#115

Deployment dependency: stack previews require the generator from the playbooks feature branch, installed on the backend and selected through RANGE42_PLATFORM_PLAYBOOKS_DIR. The container also includes the file-transfer tool needed by the native workflow.

Validation at revision a6d3b6b:

• Focused native, platform, runtime and resource suite: 71 tests passed.
• Deployed API passed authenticated readiness checks in the shared PVE test environment.
• Live full-stack preview returned HTTP 200 with 11 VMs and 521 project files.
• Live UI checks against this API covered stack creation, Git save and opening the native deployment form with a ready context. These checks did not provision a new child stack.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-28T08:10:03.291989Z	a6d3b6b	PR opened

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[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: a6d3b6be02

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[chatgpt-codex-connector]

Move runtime fingerprinting off the event loop

When requires_native_contract is enabled and a scenario requests an optional bootstrap feature, this synchronous call runs from the async preflight and deployment paths. runtime_snapshot() walks and hashes every declared runtime component, and native_contract() then hashes the bundle and controller trees again; with a large installed runtime this blocks the single Uvicorn worker, delaying unrelated API requests and SSE streams. Run this verification in a worker thread or reuse a safely cached verified snapshot.

Useful? React with 👍 / 👎.

[chatgpt-codex-connector]

Validate generator JSON is an object before calling .get

If an incompatible or malfunctioning installed generator emits valid JSON that is a list, scalar, or null, either .get call raises AttributeError, which is not caught by this handler. The preview endpoint therefore returns an internal 500 instead of the intended PLATFORM_COMPONENT_INVALID 422; explicitly require a dictionary before inspecting its fields.

Useful? React with 👍 / 👎.