Checkpoint source 7 workflows and in-progress diagram authoring redesign

Preserve current core, source, REST, desktop, recovery, documentation and validation work, including AGENTS.md and the development summary. This is a work-in-progress checkpoint: the new compact palette has outstanding compilation errors and native acceptance; earlier passing gates retain their documented scope.

docs/api.rst

@@ -155,8 +155,8 @@ Parsing, validation and query processing use snapshot workers, so this work
 does not hold the catalog lock or serialize unrelated model preparation.
 
 Import accepts schema-1 JSON through the shared explicit migration adapter,
-as well as schema-2, schema-3, schema-4, schema-5 and current schema-6 JSON. Source import uses the shared language parser
-and its supported migrations. Export uses schema 6 / arcadia 6. Native JSON
+as well as schema-2, schema-3, schema-4, schema-5, schema-6 and current schema-7 JSON. Source import uses the shared language parser
+and its supported migrations. Export uses schema 7 / arcadia 7. Native JSON
 replacement accepts supported older schemas through the same explicit migration.
 Only documented query parameters are accepted. In particular, appending
 ``?revision=...`` to model/source export is an error, not historical retrieval.
@@ -169,7 +169,7 @@ A source bundle contains ``entry`` and a map of ``files``. For example::
     {
       "entry": "rescue.arcadia",
       "files": {
-        "rescue.arcadia": "arcadia 6; project rescue \"Rescue\" { include \"oa/work.arcadia\"; }\n",
+        "rescue.arcadia": "arcadia 7; project rescue \"Rescue\" { include \"oa/work.arcadia\"; }\n",
         "oa/work.arcadia": "// Engineering rationale\noa_activity assess \"Assess assistance\" {}\n"
       }
     }
@@ -181,7 +181,7 @@ targets or another hosted resource. All submitted files must be reachable;
 missing files, cycles, duplicate keys, case collisions and escaping paths are
 rejected. The bundle permits at most 256 files, 32 include edges along a path,
 and 1,024 include edges in total. Model and source-byte budgets apply across
-the complete bundle, not separately per file. Current bundle syntax is source6; source3/4/5 bundles migrate explicitly while
+the complete bundle, not separately per file. Current bundle syntax is source7; source3/4/5/6 bundles migrate explicitly while
 preserving their files/includes/comments. V1/V2 single-file migration remains
 available through interchange import.
 
@@ -358,6 +358,39 @@ replacement routes as other engineering records. For example,
 The source representation uses ``sequence @alias`` references. The service
 does not execute conditions or simulate a process.
 
+Caller-qualified process and chain links
+----------------------------------------
+
+Schema 7 adds the closed ``RelationBody.ContextualLink`` payload::
+
+    {
+      "ContextualLink": {
+        "owner": "<caller process UUID>",
+        "source": {"references": [], "occurrence": "<direct X occurrence UUID>"},
+        "target": {"references": ["<R1 reference occurrence UUID>"],
+                   "occurrence": "<B occurrence UUID in referenced definition>"},
+        "purpose": {"Precedence": {"guard": "check accepted"}}
+      }
+    }
+
+``references`` is an ordered path of reference-occurrence IDs, never sequence
+definition IDs; at most 64entries per endpoint. The explicit owner determines
+context and source placement. ``purpose`` is exactly Precedence with string
+guard, Exchange with work-exchange UUID, or CommonWork with work UUID. Only
+Precedence contributes ordering; the other purposes preserve assembly incidence.
+Both paths empty with Precedence must use the existing SequenceLink constructor.
+Query these records with ``relations?kind=ContextualLink``. Ordinary create/edit,
+source replacement and JSON replacement share the same owner/path/purpose checks.
+
+R1.B and R2.B remain separate caller contributions even if B has one definition
+UUID. Deleting a typed path/leaf/owner/purpose dependency removes the whole link;
+retargeting an invalid surviving link requires explicit repair. No path shortening,
+implicit work duplication or fallback to a whole reference is permitted. Authored
+path entries count toward the 50,000 ordered-reference budget. Resolver cache state
+does not change validity. Contextual analysis has separate 50,000 node/100,000 edge
+limits and explicitly reports incomplete expansion. See language.rst4.2.1 for
+caller-qualified diagnostics and synthetic-boundary rules.
+
 Typed scenarios and message values
 ----------------------------------
 
@@ -403,7 +436,7 @@ contract in the same transaction when removing a used interface allocation.
 Explicit schema1/2/3 migration preserves prior identities and typed ports. Reports
 add semantic defaults, generated interface allocations and unresolved message
 values. Old source3 bundles retain files/includes/comments during upgrade; all
-current exports use schema6/source6. Reading an old envelope does not write it or
+current exports use schema7/source7. Reading an old envelope does not write it or
 advance its ETag. Canonical exports omit transient migration reports.
 
 Validation
@@ -419,7 +452,7 @@ or::
 
 or::
 
-    {"format":"source-project", "source_project":{"entry":"rescue.arcadia", "files":{"rescue.arcadia":"arcadia 6; project rescue \"Rescue\" {}"}}}
+    {"format":"source-project", "source_project":{"entry":"rescue.arcadia", "files":{"rescue.arcadia":"arcadia 7; project rescue \"Rescue\" {}"}}}
 
 A well-formed validation request returns 200 with ``valid`` and ``issues`` even
 if its candidate is invalid, including a model record that fails typed decoding.
@@ -492,7 +525,7 @@ retain the accepted model, source bundle, revision and ETag. Reading a state
 view has no semantic or persistence side effects.
 
 Source-6 communication and saved views
--------------------------------------
+--------------------------------------
 
 The same import, replacement and command endpoints admit OA
 ``CommunicationMean { source, target, oriented, items }`` and root-level
@@ -511,13 +544,43 @@ references from both layers; ordinary projections require the diagram's layer.
 These presentation choices preserve semantic records, routes, placements and
 the automatic port positions derived from unfiltered eligible exchanges.
 
-Earlier schema/source versions reject the new constructors, category review
+Schema/source versions 1–5 reject the new constructors, category review
 facts and explicit ``view_options`` field, including an empty object. Their
-frozen readers migrate accepted content to schema/source 6 with default view
+frozen readers migrate accepted content to schema/source 7 with default view
 options. The OpenAPI document describes current records; it is not a permissive
-union of historical input formats. Source-6 integration and release acceptance
+union of historical input formats. Source-7 integration and release acceptance
 are tracked separately in the release coverage audit.
 
+Explicit interface-operation identity
+-------------------------------------
+
+``OccurrenceBody.Exchange.operation`` is optional. Absent/null retains ordinary
+channel semantics and is omitted in canonical output. ``{"allocation":null}``
+(or an empty object) retains explicit unresolved operation intent. A selected
+``{"allocation":"<InterfaceItemAllocation UUID>"}`` identifies that exact
+allocation, including for parameterless operations sharing one channel. These
+records are closed; unknown fields are rejected. Earlier schema/source versions
+reject the operation field even when explicitly null and reject ContextualLink
+and their new semantic facets. Migration never guesses an operation from names,
+message values or a channel's item set.
+
+Selection is valid only for SA BoundaryInterface Call/Asynchronous messages.
+Core proves actual Standard component-port Requires/Provides roles, compatible
+interfaces exposing the same allocation, actual channel direction and allowed
+transmission protocol. Reply stores no operation and derives it from its exact
+Call; a separate return channel still needs its own valid carried-item/endpoint
+contract, including a void return. Selected message values use the exact operation
+signature. Unresolved intent preserves live expressions and checks their paths
+with an incomplete-signature warning; it does not substitute the channel union.
+
+Allocation deletion clears selection to unresolved only within an otherwise
+valid whole candidate. Removing the sole allocation can refuse atomically while
+a channel still carries its now-unadmitted item; repair every affected channel
+explicitly in the same batch. A surviving same-item allocation may keep a channel
+valid, but is never silently selected. Reselection validates retained values
+without pruning them. The service uses the same source/history boundary as
+graphical editing. See language.rst4.3.1 for the complete contract.
+
 Cross-layer transitions
 -----------------------
 
@@ -525,11 +588,19 @@ Preview accepts the shared ``TransitionRequest`` record, including direction
 (``OaToSa`` or ``SaToOa``), sources, dependency scope, mappings, selected fields,
 conflict resolutions and optional destination diagram. All fields are explicit
 in OpenAPI. At most 100 sources, 200 mappings, 200 communication endpoint
-decisions and 400 field resolutions are
+decisions, 200 operation omissions and 400 field resolutions are
 accepted. A conflict-free plan must fit the same 200-command transaction limit
 and model/source-capacity limits. A conflict-free preview also checks source
 writeback, so its commands can update the same accepted authored workspace.
 
+SA→OA abstraction of explicit operation intent requires ``operation_omissions``
+(omitted means empty). Each closed record contains the selected invocation's
+``source`` UUID and a nonempty ``rationale`` string. Missing, duplicate,
+irrelevant or wrong-direction omissions reject. Reply derives its Call's
+abstraction and has no second writable operation choice. Source operation
+identity/values remain intact; target facts are mapped and validated. Preview
+and Apply enforce the same 200 omission limit for ordinary and semantic transitions.
+
 OA ``CommunicationMean`` maps to an SA ``BoundaryExchange`` through an explicit
 ``communication_endpoints`` array (omitted means empty). Each decision identifies
 the source communication means and both ``source_port`` and ``target_port``.
@@ -660,7 +731,8 @@ not persist plans, tokens or review sessions.
 Requests allow 100 sources, trace choices and reviews; 200 mappings, candidates
 and accepted impacts; 5,000 canonical reference mappings; and 5,000 facet
 resolutions plus resets across all reviews. The legacy 400 prose-resolution
-limit and 200-command transaction limit still apply. Query has the same 5,000
+limit, 200 communication endpoint decisions, 200 operation omissions and
+200-command transaction limit still apply. Query has the same 5,000
 reference-map limit. Core bounded linked traversal errors remain observable as
 semantic rejection; no truncated result silently claims complete review.