BodyNode carries no id, though the Neo4j projection mints one for every body node

[rahlk]

Spec: 2026-09-05-body-node-id-in-analysis-json.md

Problem

BodyNode carries no id field while PyCallable does (codeanalyzer/schema/py_schema.py:127 vs :354). The id exists: the Neo4j projection mints <callable-id>@<local> for every :PyBodyNode via _global_ordinal (neo4j/project.py:123), which mirrors IdentityMap.global_id (dataflow/identity.py:84). So the analyzer computes the id, projects it to the graph, and drops it from the JSON model. PyCallableParameter (py_schema.py:286) has the same gap.

A consumer holding a BodyNode from the JSON path cannot name it. The only workaround is composing f"{callable.id}@{body_key}" in the consumer, which reimplements the can:// grammar outside the analyzer and drifts silently. python-sdk did exactly that on signature instead of id (python-sdk#320). On the Odoo graph these are the dataflow endpoints:

kind	count
actual_in	229,035
formal_in	197,847
actual_out	133,267
formal_out	120,172
call	77,332
statement	55,169

Scope boundary

Adds id to BodyNode and PyCallableParameter in analysis.json only. Not PyCallsite (legacy list, folded into body nodes by #120). Not class attributes or variables (their ids are being redone under #173). No Neo4j change: the graph already carries the id. No schema_version bump.

Goals

• BodyNode.id: str = "", populated for every body node at every level it exists (L1 call, L3 statements and @entry/@exit, L4 param vertices), value = _global_ordinal(callable.id, local_key)
• PyCallableParameter.id: str = "", value = f"{callable.id}@formal_in:{i}" for position i in parameters
• Stamp from the one existing function, not inlined at the four construction sites (schema/l1_body.py:12, dataflow/builder.py:276,279,291,538)
• Parity test: for a fixture at -a 4, every body[k].id equals the PyBodyNode merge key the projector emits for k
• Formal-order test at -a 4: for every callable and every i, body[parameters[i].id].of == parameters[i].name
• Test that a call node's id is never equal to its callee
• Monotonicity CI green
• .claude/SCHEMA_DECISIONS.md entry; README schema section and docs/skills/analyzing-canpy-graphs vocabulary updated

Caveats and known risks

• parameters[i].id names a formal_in node that exists in body only at L4. Below L4 it is a forward reference by design; document it rather than emitting it conditionally.
• Python's formal_in vertices for captures and globals follow the declared parameters (dataflow/sdg.py:145), so indices past len(parameters) are not parameters. The formal-order test only covers 0..len(parameters)-1.
• A cached analysis.json from 1.4.0 parses (default ""), and the analyzer version guard rebuilds it, so no stale id-less payload is served.

Definition of done

• Both tests above fail on main and pass after.
• analysis.json diff against a 1.4.0 fixture shows only added id keys.
• Full test suite green.
• Ships as codeanalyzer-python 1.5.0; python-sdk#320 unblocked.