Add the rough power balance module for early design phases

In LPH 2/3 there are no circuits yet, but the office needs a power
balance by DIN 276 cost group, as in the Excel template "Leistungsbilanz -
KG400": each trade enters consumers by piece or by area (W/m²) with GLF
and cos phi; the balance sums AV and SV per cost group, adds a reserve and
derives the maximum current.

The module is separate from the circuit structure: own tables
(migration 0010), own folder src/estimate-balance and an import-free
shared calculation used by API and UI. Writes go through project commands
(estimate-balance.insert/.update/.delete with complete documents), so
revision checks and Undo/Redo apply; it is not part of project snapshots
or transfer yet. A comparison endpoint sums the device rows of all circuit
lists by cost group (longest prefix) against the estimate.

The UI adds a sidebar entry, a list of Stände (template KG 400, empty or
copy) and a spreadsheet-like editor with autosave, AMEV picker for the
GLF, totals, reserve, maximum current, comparison table and print layout.
The tests reproduce the template example exactly (143.24 kW, 148.48 kVA,
157.56 kW / 163.33 kVA with 10 % reserve, 235.75 A). See
docs/estimate-balance.md and issue #7.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/db/repositories/estimate-balance-project-command.repository.ts

@@ -0,0 +1,132 @@
+import { eq } from "drizzle-orm";
+import {
+  assertEstimateBalanceDeleteProjectCommand,
+  assertEstimateBalanceInsertProjectCommand,
+  assertEstimateBalanceUpdateProjectCommand,
+  createEstimateBalanceDeleteProjectCommand,
+  createEstimateBalanceInsertProjectCommand,
+  createEstimateBalanceUpdateProjectCommand,
+  estimateBalanceDeleteCommandType,
+  estimateBalanceInsertCommandType,
+  estimateBalanceUpdateCommandType,
+  normalizeEstimateBalanceSnapshot,
+  sameEstimateBalance,
+  type EstimateBalanceProjectCommand,
+} from "../../estimate-balance/domain/estimate-balance-command.model.js";
+import type {
+  EstimateBalanceProjectCommandStore,
+  ExecuteEstimateBalanceCommandInput,
+} from "../../estimate-balance/domain/estimate-balance-project-command.store.js";
+import type { EstimateBalanceSnapshot } from "../../shared/estimate-balance/estimate-balance.js";
+import type { AppDatabase } from "../database-context.js";
+import { estimateBalances } from "../schema/estimate-balances.js";
+import { projects } from "../schema/projects.js";
+import { executeProjectCommandTransaction } from "./project-command-transaction.persistence.js";
+import {
+  deleteEstimateBalance,
+  insertEstimateBalance,
+  readEstimateBalances,
+} from "./estimate-balance.persistence.js";
+
+export class EstimateBalanceProjectCommandRepository
+  implements EstimateBalanceProjectCommandStore
+{
+  constructor(private readonly database: AppDatabase) {}
+
+  execute(input: ExecuteEstimateBalanceCommandInput) {
+    return executeProjectCommandTransaction(this.database, input, (tx) =>
+      this.applyCommand(tx, input.projectId, input.command)
+    );
+  }
+
+  private applyCommand(
+    database: AppDatabase,
+    projectId: string,
+    command: EstimateBalanceProjectCommand
+  ): EstimateBalanceProjectCommand {
+    switch (command.type) {
+      case estimateBalanceInsertCommandType:
+        assertEstimateBalanceInsertProjectCommand(command);
+        return this.insert(database, projectId, command.payload.balance);
+      case estimateBalanceDeleteCommandType:
+        assertEstimateBalanceDeleteProjectCommand(command);
+        return this.delete(database, projectId, command.payload.balance);
+      case estimateBalanceUpdateCommandType:
+        assertEstimateBalanceUpdateProjectCommand(command);
+        return this.update(
+          database,
+          projectId,
+          command.payload.expected,
+          command.payload.target
+        );
+    }
+  }
+
+  private insert(
+    database: AppDatabase,
+    projectId: string,
+    balance: EstimateBalanceSnapshot
+  ) {
+    if (balance.projectId !== projectId) {
+      throw new Error("Estimate-balance snapshot does not belong to project.");
+    }
+    const project = database
+      .select({ id: projects.id })
+      .from(projects)
+      .where(eq(projects.id, projectId))
+      .get();
+    if (!project) {
+      throw new Error("Project does not exist.");
+    }
+    const existing = database
+      .select({ id: estimateBalances.id })
+      .from(estimateBalances)
+      .where(eq(estimateBalances.id, balance.id))
+      .get();
+    if (existing) {
+      throw new Error("Estimate-balance id already exists.");
+    }
+    const normalized = normalizeEstimateBalanceSnapshot(balance);
+    insertEstimateBalance(database, normalized);
+    return createEstimateBalanceDeleteProjectCommand(normalized);
+  }
+
+  private delete(
+    database: AppDatabase,
+    projectId: string,
+    expected: EstimateBalanceSnapshot
+  ) {
+    this.assertPersisted(database, projectId, expected, "deletion");
+    if (deleteEstimateBalance(database, projectId, expected.id) !== 1) {
+      throw new Error("Estimate balance could not be deleted.");
+    }
+    return createEstimateBalanceInsertProjectCommand(expected);
+  }
+
+  private update(
+    database: AppDatabase,
+    projectId: string,
+    expected: EstimateBalanceSnapshot,
+    target: EstimateBalanceSnapshot
+  ) {
+    this.assertPersisted(database, projectId, expected, "update");
+    // Group and row ids stay stable; replacing the whole document keeps the
+    // command exact and its inverse trivially the swapped pair.
+    deleteEstimateBalance(database, projectId, expected.id);
+    const normalized = normalizeEstimateBalanceSnapshot(target);
+    insertEstimateBalance(database, normalized);
+    return createEstimateBalanceUpdateProjectCommand(normalized, expected);
+  }
+
+  private assertPersisted(
+    database: AppDatabase,
+    projectId: string,
+    expected: EstimateBalanceSnapshot,
+    action: string
+  ) {
+    const [persisted] = readEstimateBalances(database, projectId, expected.id);
+    if (!persisted || !sameEstimateBalance(persisted, expected)) {
+      throw new Error(`Estimate balance changed before ${action}.`);
+    }
+  }
+}

src/db/repositories/estimate-balance.persistence.ts

@@ -0,0 +1,121 @@
+import { and, asc, eq, inArray } from "drizzle-orm";
+import type { EstimateBalanceSnapshot } from "../../shared/estimate-balance/estimate-balance.js";
+import type { AppDatabase } from "../database-context.js";
+import {
+  estimateBalances,
+  estimateGroups,
+  estimateRows,
+} from "../schema/estimate-balances.js";
+
+/** Reads complete balance documents of a project, ordered like the UI shows them. */
+export function readEstimateBalances(
+  database: AppDatabase,
+  projectId: string,
+  balanceId?: string
+): EstimateBalanceSnapshot[] {
+  const balances = database
+    .select()
+    .from(estimateBalances)
+    .where(
+      balanceId
+        ? and(
+            eq(estimateBalances.projectId, projectId),
+            eq(estimateBalances.id, balanceId)
+          )
+        : eq(estimateBalances.projectId, projectId)
+    )
+    .orderBy(asc(estimateBalances.sortOrder), asc(estimateBalances.id))
+    .all();
+  if (!balances.length) {
+    return [];
+  }
+  const groups = database
+    .select()
+    .from(estimateGroups)
+    .where(inArray(estimateGroups.balanceId, balances.map((balance) => balance.id)))
+    .orderBy(asc(estimateGroups.sortOrder), asc(estimateGroups.id))
+    .all();
+  const rows = groups.length
+    ? database
+        .select()
+        .from(estimateRows)
+        .where(inArray(estimateRows.groupId, groups.map((group) => group.id)))
+        .orderBy(asc(estimateRows.sortOrder), asc(estimateRows.id))
+        .all()
+    : [];
+  return balances.map((balance) => ({
+    id: balance.id,
+    projectId: balance.projectId,
+    name: balance.name,
+    workStage: balance.workStage,
+    dateIso: balance.dateIso,
+    reserveAvPercent: balance.reserveAvPercent,
+    reserveSvPercent: balance.reserveSvPercent,
+    sortOrder: balance.sortOrder,
+    groups: groups
+      .filter((group) => group.balanceId === balance.id)
+      .map((group) => ({
+        id: group.id,
+        costGroup: group.costGroup,
+        title: group.title,
+        editor: group.editor,
+        sortOrder: group.sortOrder,
+        rows: rows
+          .filter((row) => row.groupId === group.id)
+          .map(({ groupId: _groupId, ...row }) => row),
+      })),
+  }));
+}
+
+/** Writes a complete balance document (the caller removed an older version first). */
+export function insertEstimateBalance(
+  database: AppDatabase,
+  balance: EstimateBalanceSnapshot
+) {
+  database
+    .insert(estimateBalances)
+    .values({
+      id: balance.id,
+      projectId: balance.projectId,
+      name: balance.name,
+      workStage: balance.workStage,
+      dateIso: balance.dateIso,
+      reserveAvPercent: balance.reserveAvPercent,
+      reserveSvPercent: balance.reserveSvPercent,
+      sortOrder: balance.sortOrder,
+    })
+    .run();
+  for (const group of balance.groups) {
+    database
+      .insert(estimateGroups)
+      .values({
+        id: group.id,
+        balanceId: balance.id,
+        costGroup: group.costGroup,
+        title: group.title,
+        editor: group.editor,
+        sortOrder: group.sortOrder,
+      })
+      .run();
+    if (group.rows.length) {
+      database
+        .insert(estimateRows)
+        .values(group.rows.map((row) => ({ ...row, groupId: group.id })))
+        .run();
+    }
+  }
+}
+
+/** Removes a balance with its groups and rows (foreign keys cascade). */
+export function deleteEstimateBalance(
+  database: AppDatabase,
+  projectId: string,
+  balanceId: string
+) {
+  return database
+    .delete(estimateBalances)
+    .where(
+      and(eq(estimateBalances.projectId, projectId), eq(estimateBalances.id, balanceId))
+    )
+    .run().changes;
+}

src/db/repositories/estimate-balance.repository.ts

@@ -0,0 +1,60 @@
+import { asc, eq } from "drizzle-orm";
+import type {
+  DetailedDeviceRowPower,
+  EstimateBalanceSnapshot,
+} from "../../shared/estimate-balance/estimate-balance.js";
+import { calculateRowTotalPower } from "../../domain/calculations/circuit-power-calculation.js";
+import type { AppDatabase } from "../database-context.js";
+import { circuitDeviceRows } from "../schema/circuit-device-rows.js";
+import { circuitLists } from "../schema/circuit-lists.js";
+import { circuits } from "../schema/circuits.js";
+import { estimateBalances } from "../schema/estimate-balances.js";
+import { readEstimateBalances } from "./estimate-balance.persistence.js";
+
+/** Read side of the estimate-balance module; writes go through commands. */
+export class EstimateBalanceRepository {
+  constructor(private readonly database: AppDatabase) {}
+
+  listByProject(projectId: string): EstimateBalanceSnapshot[] {
+    return readEstimateBalances(this.database, projectId);
+  }
+
+  findById(projectId: string, balanceId: string): EstimateBalanceSnapshot | null {
+    return readEstimateBalances(this.database, projectId, balanceId)[0] ?? null;
+  }
+
+  nextSortOrder(projectId: string): number {
+    const rows = this.database
+      .select({ sortOrder: estimateBalances.sortOrder })
+      .from(estimateBalances)
+      .where(eq(estimateBalances.projectId, projectId))
+      .orderBy(asc(estimateBalances.sortOrder))
+      .all();
+    return rows.length ? Math.max(...rows.map((row) => row.sortOrder)) + 1 : 0;
+  }
+
+  /**
+   * Device rows of all circuit lists of the project with their total power
+   * (quantity · power per unit · device GZF, like the circuit tree).
+   */
+  listDetailedDeviceRowPower(projectId: string): DetailedDeviceRowPower[] {
+    return this.database
+      .select({
+        costGroup: circuitDeviceRows.costGroup,
+        quantity: circuitDeviceRows.quantity,
+        powerPerUnit: circuitDeviceRows.powerPerUnit,
+        simultaneityFactor: circuitDeviceRows.simultaneityFactor,
+        cosPhi: circuitDeviceRows.cosPhi,
+      })
+      .from(circuitDeviceRows)
+      .innerJoin(circuits, eq(circuits.id, circuitDeviceRows.circuitId))
+      .innerJoin(circuitLists, eq(circuitLists.id, circuits.circuitListId))
+      .where(eq(circuitLists.projectId, projectId))
+      .all()
+      .map((row) => ({
+        costGroup: row.costGroup,
+        kw: calculateRowTotalPower(row.quantity, row.powerPerUnit, row.simultaneityFactor),
+        cosPhi: row.cosPhi,
+      }));
+  }
+}