[4/4] feat(web): templates, dashboard, and node views

[immanuel-peter]

What

Complete the control-plane console with template build/list/detail, cluster dashboard panels, and node inventory/detail pages. After this PR, the tree matches the full feat/agentenv-webui reference.

Why

Templates, dashboard, and nodes share dashboard formatting helpers and admin-token-gated node APIs; shipping them together finishes issue #6 without bloating the earlier auth/sandbox reviews.

Related issue

Closes #6

Scope and non-goals

In scope

• Template list/build/detail + build log viewer
• Dashboard overview panels
• Node list/detail (admin-token gated; degrades when token absent)

Non-goals (v1)

• Browser terminal, filesystem browser, or in-sandbox process execution
• Node drain/delete/scheduling configuration
• Scheduler gRPC access (Gateway HTTP only)

Design and behavior changes

• Dashboard aggregates Gateway sandbox/template/snapshot/node reads with manual/optional refresh
• Node pages require admin token; other console pages remain usable without it
• Reuses shared helpers (LocalTime, copy button, formatters) from earlier stack PRs

Compatibility and operations

• Public API or generated protocol: N/A
• Configuration or defaults: N/A beyond earlier stack PRs
• Snapshot manifest, artifact layout, or storage format: N/A
• Upgrade and rollback: additive UI-only
• Host requirements, permissions, ports, or dependencies: same as prior stack PRs

Validation

• make fmt
• make clippy
• make test-unit
• Relevant Rust integration tests
• make -C services test (deploy path touched in PR 1; run on full stack)
• Generated clients/server regenerated with the documented make target
• Documentation updated
• Benchmarks or performance comparison completed

Commands and results:

# Validated on the full reference tip / each stacked branch build:
make fmt                                 # pass
make clippy                              # pass
make test-unit PROFILE=debug             # pass
make -C services fmt-check vet test build # pass
cd web && pnpm install --frozen-lockfile && pnpm lint && pnpm build  # pass
docker build -f deploy/docker/Dockerfile.web -t agentenv-web:validate web  # pass
mdbook build docs                        # pass

Skipped checks and reasons:

• Rust integration tests: no **.rs / Cargo changes
• Generated clients/server: no OpenAPI/codegen source changes
• Benchmarks: UI-only change

Risks and reviewer notes

• Layer-only compare: immanuel-peter/AgentENV@feat/web-3-sandboxes-snapshots...feat/web-4-templates-dashboard-nodes
• Full reference branch (lossless tip): feat/agentenv-webui
• Depends on [1/4] feat(web): scaffold control-plane console and deploy wiring #76, [2/4] feat(web): Gateway connection settings and session cookies #77, and [3/4] feat(web): sandbox and snapshot management views #78

Stack

Merge order: #76 → #77 → #78 → #79

Checklist

• The PR contains one coherent change and no unrelated formatting or refactoring.
• New behavior is covered by tests, or I explained why testing is impractical.
• Logs and examples contain no credentials, tokens, or private registry information.
• I did not manually edit generated code without updating its source and regenerating it.