refactor(db): port runtime ops to sqlc (#79)

Tranche 5 — all 24 raw sites in runtime.go. Adds runtime.sql with the
legacy-column COALESCE loader (type/image/command/git_repo fall back to
service_type/image_name/start_command/source_url), env-var reads,
sibling refs, deployed-image concat, and conditional published-port /
replica writes. Status transitions reuse SetServiceStatus.

loadReadableService now shares GetServiceRuntimeWithOwner — the projects
join is safe (FK) and drops a duplicated 24-column select.

TestRuntimeLiveInvariants verifies the COALESCE chain against a service
seeded with only legacy columns, plus refs, port, variables, agent
listing, image concat, and conditional updates on live Postgres.

Generated with [Devin](https://devin.ai)

Co-authored-by: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

app/backend/sqlc/queries/runtime.sql

@@ -0,0 +1,47 @@
+-- name: ListNodeAgentsForService :many
+SELECT DISTINCT node_agent_id FROM container_instances WHERE service_id = $1;
+
+-- name: ListServiceVariableValues :many
+SELECT key, value FROM environment_variables WHERE service_id = $1;
+
+-- name: ListServiceVariablesWithSecret :many
+SELECT key, value, COALESCE(is_secret, false) AS is_secret
+FROM environment_variables WHERE service_id = $1;
+
+-- name: ListProjectServiceRefs :many
+SELECT id, name FROM services WHERE project_id = $1;
+
+-- name: GetServicePort :one
+SELECT COALESCE(port, 0) AS port FROM services WHERE id = $1;
+
+-- name: GetServiceVariableValue :one
+SELECT value FROM environment_variables WHERE service_id = $1 AND key = $2;
+
+-- name: GetServiceRuntimeWithOwner :one
+SELECT s.id, s.project_id, s.name,
+       COALESCE(s.type, s.service_type, '') AS type, COALESCE(s.status, '') AS status,
+       COALESCE(s.image, s.image_name, '') AS image, COALESCE(s.command, s.start_command, '') AS command,
+       COALESCE(s.environment, '') AS environment, COALESCE(s.git_repo, s.source_url, '') AS git_repo,
+       COALESCE(s.git_branch, '') AS git_branch, COALESCE(s.build_path, '') AS build_path,
+       COALESCE(s.cpu, '') AS cpu, COALESCE(s.memory, '') AS memory,
+       COALESCE(s.replicas, 1) AS replicas, COALESCE(s.port, 0) AS port,
+       COALESCE(s.domain, '') AS domain, COALESCE(s.healthcheck_path, '') AS healthcheck_path,
+       COALESCE(s.restart_policy, 'unless-stopped') AS restart_policy,
+       COALESCE(s.builder, 'auto') AS builder, COALESCE(s.cpu_reserve, '') AS cpu_reserve,
+       COALESCE(s.memory_reserve, '') AS memory_reserve, COALESCE(s.static_build_cmd, '') AS static_build_cmd,
+       COALESCE(s.static_dir, '') AS static_dir,
+       s.created_at, s.updated_at, p.owner_id
+FROM services s
+JOIN projects p ON s.project_id = p.id
+WHERE s.id = $1;
+
+-- name: GetLastDeployedImage :one
+SELECT (image_name || ':' || image_tag)::text AS image FROM deployments
+WHERE service_id = $1 AND status = 'deployed' AND image_name <> ''
+ORDER BY created_at DESC LIMIT 1;
+
+-- name: SetServicePublishedPort :exec
+UPDATE services SET published_port = $1 WHERE id = $2 AND published_port <> $1;
+
+-- name: SetServiceReplicas :exec
+UPDATE services SET replicas = $1, updated_at = $2 WHERE id = $3;