Update print view and documentation for logical feeds

AGENTS.md

@@ -52,7 +52,8 @@ See `docs/current-architecture.md` for the complete module and request flow.
 - Device rows inside a circuit do not have their own equipment identifiers.
 - Protection and cable data belong to the circuit, not to individual devices.
 - Device-level values include quantity, power per unit, simultaneity factor, cosPhi, room data, cost group and category.
-- Circuit total power is the sum of all device rows in that circuit.
+- Circuit total power is the sum of all device rows in that circuit plus the
+  read-only loads of logically linked downstream boards on that feeder circuit.
 - Existing equipment identifiers must never be changed automatically.
 - Renumbering is always an explicit user action.
 
@@ -284,16 +285,19 @@ not change the project revision or undo/redo stacks. Restoring a server-stored
 snapshot verifies its checksum and the current-state hash, replaces supported
 project data atomically and records a new `restore` revision with a complete
 inverse command. Restore can therefore be undone and redone after a restart.
-Current snapshot schema version 8 additionally stores the optional net room
-area `rooms[].areaM2` (see `docs/building-structure.md`); versions 1 to 7 are
-upgraded with `areaM2 = null`. Version 7 stores the project buildings and
+Current snapshot schema version 9 additionally stores
+`feedingDistributionBoardId` and `feedingCircuitId` on distribution boards;
+versions 1 to 8 are upgraded with both references set to `null`. Version 8
+stores the optional net room area `rooms[].areaM2` (see
+`docs/building-structure.md`); versions 1 to 7 are upgraded with
+`areaM2 = null`. Version 7 stores the project buildings and
 `floors[].buildingId`; versions 1 to 6 are upgraded with no buildings and
 `buildingId = null`. Version 6 stores the
 distribution-board info fields `boardNumber`, `location`, `fedFrom` and
 `remark` and the project cover fields `siteAddress`, `workStage`,
 `projectLead` and `projectEditor`; all older supported versions are upgraded
 with `null` for these fields.
-Stored named and automatic snapshots of every supported version (1 to 8)
+Stored named and automatic snapshots of every supported version (1 to 9)
 remain restorable; they are upgraded while parsing. Version 5 stores
 the manual quantity share of every CircuitDeviceRow. Version 4 snapshots are upgraded with
 `manualQuantity = quantity`; they already contain the complete confirmed
@@ -309,7 +313,7 @@ project graph.
 Project-wide Revit CSV configuration uses
 `external-csv-configuration.update`. Its complete expected/target snapshot is
 persisted through the shared project-command transaction, so create, update,
-delete, Undo and Redo are revision-safe. Snapshot schema 5-8, restore and portable
+delete, Undo and Redo are revision-safe. Snapshot schema 5-9, restore and portable
 project duplication preserve the configuration; duplication remaps its internal
 id and project link.
 The project page exposes the Revit CSV modal. It edits the complete
@@ -323,7 +327,7 @@ immutable import batches with original bytes plus the classified cell matrix,
 normalized source-room mappings and external objects unique by
 `(sourceId, ifcGuid)`. Source values, planning values and overrides are separate.
 The general external-model repository is read-only; runtime writes belong only
-to typed command adapters. Snapshot/restore and portable project transfer schema versions 5-8
+to typed command adapters. Snapshot/restore and portable project transfer schema versions 5-9
 capture the complete external state and remap every internal UUID and link while
 preserving IFCGUIDs, source values, original bytes and the classified matrix.
 Import batches additionally store the monotonic project CSV configuration
@@ -463,22 +467,34 @@ snapshot contains the group, optional component protections, complete circuits,
 circuit protections and all device-row link/override metadata. Delete
 re-captures and compares the subtree before cascading; restore preserves every
 UUID in foreign-key-safe order.
-The circuit-tree read model exposes fixed `headerComponents`, group-owned
+The project-wide circuit-tree read model exposes fixed `headerComponents`, group-owned
 `components`, `footerComponents`, optional group category/number and optional
 one-to-one protection DTOs for circuits and group components. These are
 the only supported circuit-protection source; no flat compatibility fields remain.
+It resolves logical board feeds once for the complete project and adds each
+downstream board's demand after its own board simultaneity factor to the chosen
+feeding circuit as a read-only virtual row. Recursive chains and several boards
+on one circuit are supported. A board-only link affects hierarchy but adds no
+load until a feeding circuit is selected.
 Distribution-board floor assignment and a project-enabled supply type use
 `distribution-board.update`; both values are snapshot/export fields and one
 persistent undo step.
-The same command (still schema version 1, additively extended) carries the
+The same command uses schema version 2 for the logical
+`feedingDistributionBoardId` and optional matching `feedingCircuitId` together
+with the existing fields. Version-1 history commands remain executable and do
+not change logical feed references. The command rejects self-links, cycles and
+circuits from another board. The
 board info-card fields `boardNumber`, `location`, `fedFrom` and `remark`
 (migration `0007`). They are nullable, trimmed planner values; the PUT route
 only includes submitted info fields in the command and its inverse. An empty
 board with info values is no longer an unchanged setup, so history deletion of
 it is rejected like a changed simultaneity factor. Populated-subtree commands
 stored before these fields existed are normalized to `null` values
-(`normalizeDistributionBoardSubtreeSnapshot`). `fedFrom` is deliberately free
-text: the logical link to the feeding board/circuit is an open design decision.
+(`normalizeDistributionBoardSubtreeSnapshot`). `fedFrom` remains free text for
+external feeds and notes; project-board feeds use the two UUID references.
+Deleting a referenced board or feeding circuit is blocked in every direct,
+subtree and history-only removal path. Board copies retain their incoming feed,
+and project duplication remaps both references.
 These fields are intended to be prefillable from Revit parameters later, but
 only through the Phase 14 rules (preview, explicit confirmation, no silent
 overwrite).
@@ -521,9 +537,10 @@ Required operations:
   `<thead>` so it repeats on printed pages. PDF export uses the browser print
   dialog; page size, margins and "Seite x von y" come from injected named
   `@page` rules (`lb-portrait`, `lb-landscape`).
-- The board hierarchy and "Σ inkl. unterlagert" in the overview are
-  PRELIMINARY (text match of `fedFrom` against board number/name, plain sum,
-  no upstream simultaneity factor). Replace this once the feed link is modeled.
+- The board hierarchy follows logical board ids. The overview shows power
+  before board GZF and demand including linked downstream boards; it does not
+  add a second cumulative column. Board plans render downstream-board loads as
+  read-only rows. `fedFrom` groups only external root feeds.
 - Colors/fonts follow the kbp corporate design (`--pd-*` variables in
   `print-document.css`). Empty cover values are shown as
   "[ergänzen]"; the Planstände editor column shows the project's current
@@ -701,9 +718,9 @@ for the early-phase power balance by DIN 276 cost group (see
 - full electrical sizing
 - multi-user/PostgreSQL operation
 - supported production deployment
-- logical feed link between distribution boards (`fedFrom` stays free text
-  until the project owner decides whether it references a board, a feeding
-  circuit or both) and the resulting hierarchical power summation
+- second/replacement board feeds, including changeover semantics for SV/SiBe
+- Revit prefill proposals for logical board feeds through the Phase 14 preview
+  and explicit-confirmation workflow
 
 Do not implement these while working on an unrelated phase.