Evaluate 1st-party templates for parallel deploy via uses field

[jongio]

Audit all Azure-maintained azd templates to identify which can leverage the uses: field in azure.yaml to enable parallel provisioning and deploy via the exegraph scheduler (#7776).

Goal

Classify every 1st-party template into:

1. Independent services -- can deploy in parallel today with uses: expressing no deps (or future execution.parallel: true per feat: explicit parallel deploy opt-in for non-Aspire templates #7995)
2. Has dependencies -- services with real ordering needs (e.g., API endpoint consumed by frontend deploy hook); add uses: to express the graph while unlocking parallelism for independent services
3. Aspire-based -- already parallel via build-gate, no action needed

What to check per template

• Service-level hooks (predeploy/postdeploy) that read/write env vars or endpoints from other services
• Infrastructure outputs consumed by deploy steps
• Shared resources requiring sequential deploy access

Deliverables

• Inventory of all 1st-party templates with classification
• PRs adding uses: to templates that benefit
• Validation that azd deploy produces correct results for representative templates

Related

• feat(exegraph): graph-driven execution engine for up/provision/deploy #7776 -- exegraph execution engine
• feat: explicit parallel deploy opt-in for non-Aspire templates #7995 -- explicit parallel deploy opt-in for non-Aspire templates