Add direct diagram connections, movable ports, and contextual authoring

docs/language.html

@@ -1296,7 +1296,7 @@ capabilities with their involvement, exploitation, include, extend and
 generalization links. Decomposition and Overview retain general containment;
 Overview also exposes all relationships. Changing the projection hides
 inapplicable placements without deleting them or changing semantic records.</p>
-<p>Ports are calculated boundary anchors of visible owners, with their existing
+<p>Ports are boundary anchors of visible owners, with their existing
 semantic identity. An explicitly placed port is not rendered as a separate
 large node. Functional exchanges use their declared source/target ports;
 boundary exchanges attach to their participant ports even if those ports have
@@ -1305,13 +1305,45 @@ may terminate at a visible ancestor without creating a new port or exchange.</p>
 <p><span class="docutils literal">node</span> has an alias and identity but no display-name string. Required fields
 are <span class="docutils literal">diagram</span> and <span class="docutils literal">element</span> references. Optional fields are <span class="docutils literal">position</span>
 (record with x/y, default 0/0), <span class="docutils literal">size</span> (width/height, default 224/94), and
-<span class="docutils literal">collapsed</span> (false). Node identity is independent of its semantic element.
+<span class="docutils literal">collapsed</span> (false), and <span class="docutils literal">port_anchors</span> (empty list). Node identity is
+independent of its semantic element.
 Coordinates are absolute diagram coordinates. Placement does not alter parent,
 allocation, or realization. Hiding an element from a diagram must remain
 distinguishable from deleting it from the model.
 Changing a node's diagram preserves the placement identity, alias, coordinates,
-size, collapse state, and attached artifacts. The destination must accept the
-element's layer and must not already contain another placement of that element.</p>
+size, collapse state, manual port anchors, and attached artifacts. The destination
+must accept the element's layer and must not already contain another placement
+of that element.</p>
+<p>Each <span class="docutils literal">port_anchors</span> entry is a PortAnchor record with required <span class="docutils literal">port</span>
+reference, <span class="docutils literal">side</span> (Left, Right, Top, or Bottom), and <span class="docutils literal">offset</span> (finite
+binary32 from 0 through 1). It has no separate identity or alias. The port MUST
+be an existing Port directly owned by the placement's <span class="docutils literal">element</span>. A port MAY
+have one manual anchor per placement; different diagrams MAY position it
+independently. List order is preserved but has no positional meaning.</p>
+<p><span class="docutils literal">offset</span> measures a fraction of the complete projected owner edge, from top
+on Left/Right or from left on Top/Bottom. Zero and one denote its corners.
+The side is presentation data and MUST NOT change the port's contract,
+orientation, ownership, allocations, or connected exchanges. Absent anchors use
+automatic positioning. Empty lists are omitted in canonical JSON/source;
+earlier schema-3 input without this field hydrates as <span class="docutils literal">[]</span>.</p>
+<pre class="code text literal-block"><code>node actor_view {
+    diagram &#64;architecture; element &#64;vessel;
+    port_anchors [{ port &#64;communication; side Top; offset 0.25; }];
+}</code></pre>
+<p><span class="docutils literal">SetPortAnchor { diagram, node, anchor }</span> upserts by port identity and retains
+unrelated entries. <span class="docutils literal">RemovePortAnchor { diagram, node, port }</span> restores
+automatic positioning; it is a no-op only for an existing direct child port
+of that placement. Unknown fields, duplicate port references, non-port or
+foreign-owner references, and invalid offsets are structural errors. Each
+anchor counts as one record against <span class="docutils literal">ParseLimits.max_records</span>.</p>
+<p>These commands use the same atomic history, conditional REST transactions, and
+source writeback as other presentation edits. Source references resolve across
+files, and anchor comments follow port identity. Reidentifying a port updates
+anchor references; deleting it removes its anchors. Reparenting MUST repair
+old-owner anchors in the same transaction, for example by removing them before
+the Reparent command. Moving, resizing, arranging, or folding an owner retains
+its authored sides and fractions. Frozen schema-1/schema-2 readers do not accept
+<span class="docutils literal">port_anchors</span>; their explicit migration supplies an empty list.</p>
 <p>Each <span class="docutils literal">routes</span> entry is an EdgeRoute record with a required <span class="docutils literal">edge</span> reference
 to an existing Relation or Trace, <span class="docutils literal">waypoints</span> (default <span class="docutils literal">[]</span>), and <span class="docutils literal">label</span>
 (default <span class="docutils literal">none</span>). Route records have no separate UUID or alias. An edge occurs
@@ -1615,7 +1647,8 @@ preserve authored comments and whitespace on Apply while inserting missing
 identities. Explicit canonical export remains a separate operation. Project
 update/export distinctions are described below.
 Camera position, selection, source cursor, and undo history are not stored
-model fields. Layout and collapse state inside NodePlacement are model data.</p>
+model fields. Layout, collapse state, and manual port anchors inside
+NodePlacement are model data.</p>
 <p>The pure <span class="docutils literal">format_bundle</span> exporter uses the same typed declaration writer as
 <span class="docutils literal">format</span>. It creates a small entry file, layer/category modules, separate
 activity/function roots and behavior contexts, and separate diagrams with their