marker: forward dir= from ubridge and add per-marker direction filter

Direction field in marker.match events
=======================================

Read ubridge dir=<tx|rx> from MARK signal datagrams and forward it
as a "dir" key in the marker.match notification event.  The field is
additive -- older ubridge builds omit it and the parser leaves it null,
so consumers fall back to undirected rendering with no version coupling.
Semantics are relative to the capture node (the signal's node=<id>):
tx = capture node is sending (ingressed device-side NIO), rx = it is
receiving (ingressed link-side NIO).

Per-marker direction filter (opt-in, server-side pipeline)
==========================================================

Add a direction field to MarkerCreate and MarkerDefinitionCreate
schemas ("tx" | "rx" | null).  Plumb it through the full pipeline:

  Schema -> controller (start_marker/update_marker, marker_entry,
  _markers_for_node, update_marker_definition sync)
  -> REST/MCP handlers -> compute _ubridge_add_marker_filter +
  IOU _ubridge_apply_markers -> bridge add_packet_filter dir <tx|rx>

When set, ubridge only fires the mark handler (signal + pcap) for
packets matching the chosen direction.  null (default/legacy) = both
directions -- zero behavioural change for existing markers.

Docs and tests
==============

- docs/features/marker-traffic-insight.md: signal format updated,
  new Direction section with NIO mapping, arrow mapping, and additive
  compatibility note.
- tests/compute/marker/test_marker_manager.py: 3 new parser tests
  (dir tx/rx/absent) plus existing test extended to assert dir=None.

13 files, +123/-22, 72 tests pass (zero breakage)

gns3server/api/routes/controller/links.py

@@ -465,6 +465,7 @@ async def create_marker(
         name=name,
         bpf=marker_data.bpf,
         tag=marker_data.tag,
+        direction=marker_data.direction,
         color=marker_data.color,
         highlight_duration=marker_data.highlight_duration,
     )
@@ -508,6 +509,7 @@ async def update_marker(
         name=marker_name,
         bpf=marker_data.bpf if marker_data.bpf else None,
         tag=marker_data.tag,
+        direction=marker_data.direction,
         color=marker_data.color,
         enabled=marker_data.enabled,
         highlight_duration=marker_data.highlight_duration,

gns3server/api/routes/controller/projects.py

@@ -267,6 +267,7 @@ async def create_marker_definition(
         name=name,
         bpf=def_data.bpf,
         tag=def_data.tag,
+        direction=def_data.direction,
         color=def_data.color,
         highlight_duration=def_data.highlight_duration,
     )
@@ -292,6 +293,7 @@ async def update_marker_definition(
         name=def_name,
         bpf=def_data.bpf if def_data.bpf else None,
         tag=def_data.tag,
+        direction=def_data.direction,
         color=def_data.color,
         highlight_duration=def_data.highlight_duration,
     )

gns3server/api/routes/mcp/__init__.py

@@ -1015,6 +1015,7 @@ async def link_marker(
     name: Annotated[str | None, Field(description="Custom marker name for create action (auto-generated if omitted)")] = None,
     tag: Annotated[int | None, Field(description="Numeric tag for packet correlation")] = None,
     enabled: Annotated[bool | None, Field(description="Enable or disable the marker (for update action)")] = None,
+    direction: Annotated[str | None, Field(description="Direction filter: 'tx' for capture node sending only, 'rx' for capture node receiving only (omit for both)")] = None,
     color: Annotated[str | None, Field(description="Hex color for UI highlight, e.g. '#ff5722'")] = None,
     highlight_duration: Annotated[int | None, Field(description="UI highlight duration in milliseconds")] = None,
 ) -> list[dict[str, Any]]:
@@ -1033,7 +1034,7 @@ async def link_marker(
     and cannot be modified or deleted via this tool.
     """
     params = {"project_id": project_id, "link_id": link_id, "action": action}
-    for opt in ("bpf", "marker_name", "name", "tag", "enabled", "color", "highlight_duration"):
+    for opt in ("bpf", "marker_name", "name", "tag", "enabled", "direction", "color", "highlight_duration"):
         val = locals().get(opt)
         if val is not None:
             params[opt] = val
@@ -1050,6 +1051,7 @@ async def marker_definition(
     tag: Annotated[int | None, Field(description="Numeric tag for packet correlation")] = None,
     color: Annotated[str | None, Field(description="Hex color for UI highlight, e.g. '#ff5722'")] = None,
     highlight_duration: Annotated[int | None, Field(description="UI highlight duration in milliseconds")] = None,
+    direction: Annotated[str | None, Field(description="Direction filter: 'tx' for capture node sending only, 'rx' for capture node receiving only (omit for both)")] = None,
 ) -> list[dict[str, Any]]:
     """Manage project-level marker definitions — traffic-insight rules that apply to ALL links.
 
@@ -1065,7 +1067,7 @@ async def marker_definition(
     Common BPF examples: 'arp', 'icmp', 'ospf', 'tcp port 22', 'udp port 53'
     """
     params = {"project_id": project_id, "action": action}
-    for opt in ("bpf", "def_name", "name", "tag", "color", "highlight_duration"):
+    for opt in ("bpf", "def_name", "name", "tag", "direction", "color", "highlight_duration"):
         val = locals().get(opt)
         if val is not None:
             params[opt] = val

gns3server/api/routes/mcp/links.py

@@ -395,7 +395,7 @@ def link_marker_handler(params: dict[str, Any], gns3_ctx: dict[str, Any]) -> dic
         if not bpf:
             return {"error": "bpf is required for create action"}
         body: dict[str, Any] = {"bpf": bpf}
-        for opt in ("name", "tag", "color", "highlight_duration"):
+        for opt in ("name", "tag", "direction", "color", "highlight_duration"):
             if params.get(opt) is not None:
                 body[opt] = params[opt]
         return conn.http_call("post", base, json_data=body).json()
@@ -408,7 +408,7 @@ def link_marker_handler(params: dict[str, Any], gns3_ctx: dict[str, Any]) -> dic
 
     if action == "update":
         body = {}
-        for opt in ("bpf", "tag", "enabled", "color", "highlight_duration"):
+        for opt in ("bpf", "tag", "direction", "enabled", "color", "highlight_duration"):
             if params.get(opt) is not None:
                 body[opt] = params[opt]
         if not body:
@@ -448,7 +448,7 @@ def marker_definition_handler(params: dict[str, Any], gns3_ctx: dict[str, Any])
         if not bpf:
             return {"error": "bpf is required for create action"}
         body: dict[str, Any] = {"bpf": bpf}
-        for opt in ("name", "tag", "color", "highlight_duration"):
+        for opt in ("name", "tag", "direction", "color", "highlight_duration"):
             if params.get(opt) is not None:
                 body[opt] = params[opt]
         return conn.http_call("post", base, json_data=body).json()
@@ -461,7 +461,7 @@ def marker_definition_handler(params: dict[str, Any], gns3_ctx: dict[str, Any])
 
     if action == "update":
         body = {}
-        for opt in ("bpf", "tag", "color", "highlight_duration"):
+        for opt in ("bpf", "tag", "direction", "color", "highlight_duration"):
             if params.get(opt) is not None:
                 body[opt] = params[opt]
         if not body: