fix(event_handler): route VPC Lattice requests that carry a query string

[AtulJoshi1206]

Issue number: closes #8571

Summary

Changes

VPC Lattice puts the query string inside the request path (raw_path in V1, path in V2) and also sends it parsed. VPCLatticeEvent.path and VPCLatticeEventV2.path returned that value verbatim, and the resolvers match routes against event.path with anchored regexes. So any request with a query string got a 404 on VPCLatticeResolver and VPCLatticeV2Resolver, sync and async.

This makes path the URL path without the query string, as it is for REST API, HTTP API, Function URL and ALB events.

• V1: VPCLatticeEvent.path returns raw_path up to the first ?. raw_path itself is unchanged, and its docstring now says it includes the query string.
• V2: VPCLatticeEventV2 gets its own path property, returning path up to the first ?. The original value stays in event.raw_event["path"].
• Split rule: per RFC 3986, the first ? starts the query, so an encoded %3F stays in the path.
• Why the data classes: path feeds routing, strip_prefixes, Swagger UI's ?format=json and user code, so fixing it there gives all of them the corrected value.
• New fixtures, with the existing ones unchanged so their tests keep their meaning:
  • tests/events/vpcLatticeV2EventWithQueryString.json is the event captured from a live V2 target group in Bug: VpcLatticeV2Schema rejects every real V2 event powertools-lambda-typescript#5764, unchanged. It's the same fixture TypeScript merged in chore(ci): new pre-release 3.3.1a21 #5773.
  • tests/events/vpcLatticeEventWithQueryString.json is vpcLatticeEvent.json with the query string in raw_path, as the AWS docs show for V1.
• 17 new tests. All fail on develop and pass with this change:
  • Data classes:
    • V1 and V2 path exclude the query string, and V1 raw_path keeps it.
    • Edge cases: the root path, an empty query, a ? inside the query, and an encoded %3F in the path.
    • test_vpc_lattice_event now also checks that a path without a query is unchanged.
  • Resolvers:
    • Both route a request whose path carries the query string.
    • /orders/<order_id> with /orders/42?expand=items gives order_id == "42".
    • resolve_async is covered.
    • Both resolvers work with enable_validation=True and Annotated[int, Query(alias="order-id")].

Checks:

• event_handler, data_classes and parser suites (unit and functional): all pass.
• ruff check and ruff format --check: clean.
• mypy on vpc_lattice.py: clean.

Evidence that VPC Lattice sends the query string in the path:

• AWS VPC Lattice User Guide:
  • V1: "raw_path": "/path/to/resource?query1=value1&query2=value2".
  • V2: "path": "/?query1=value1&query2=value2", "The path of the request from the client that includes query string parameters."
• AWS Compute Blog: "raw_path": "/points?action=add".
• powertools-lambda-typescript#5764: a live V2 capture with path: '/echo?QS1=value1&QS1=value2&single=one'.

User experience

Before, for the V2 event captured in powertools-lambda-typescript#5764:

app = VPCLatticeV2Resolver()

@app.post("/echo")
def echo():
    return {"query": app.current_event.query_string_parameters}

app.resolve(event, context)  # event["path"] == "/echo?QS1=value1&QS1=value2&single=one"
# statusCode 404, body {"statusCode":404,"message":"Not found"}

After: the request reaches echo and returns 200 with {"query": {"QS1": "value1,value2", "single": "one"}}, and app.current_event.path == "/echo". Dynamic routes, strip_prefixes and /swagger?format=json now match the same way, and V1 behaves the same.

Risk: event.path no longer contains the query string.

• Code that parsed the query out of event.path should use event.query_string_parameters, or the raw value: event.raw_path (V1) or event.raw_event["path"] (V2).
• Through the resolvers these requests returned 404 before. So in practice this only affects code that reads event.path directly: data-class users (@event_source(data_class=VPCLatticeEvent) / VPCLatticeEventV2), catch-all routes, not_found handlers and middlewares.

Follow-ups (not in this PR). These have a different root cause: V2 sends every header and query string value as a list.

• aws_lambda_powertools/event_handler/middlewares/openapi_validation.py:144 calls .strip() on headers.get("content-type", ""), which is a list for V2. With enable_validation=True and a body parameter, a real V2 event fails with AttributeError: 'list' object has no attribute 'strip'.
• VpcLatticeV2Model declares headers and queryStringParameters as dict[str, str], so the parser rejects real V2 events. TypeScript fixed the same schema in powertools-lambda-typescript#5764 and chore(ci): new pre-release 3.3.1a21 #5773.
• The docs sample payloads (examples/event_handler_rest/src/getting_started_vpclattice*_resolver.json, examples/event_sources/events/vpc_lattice*_payload.json) also leave the query string out of the path.

AI assistance: prepared with Claude Code; the change was reviewed and the tests were run locally.

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[leandrodamascena]

Thanks! I reproduced the 404 with the V2 event from the TS issue and it passes with this fix. AWS docs confirm the path carries the query string in both versions, so this is correct. Approving.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.93%. Comparing base (f58cd87) to head (85113ae).
⚠️ Report is 1 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #8572   +/-   ##
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  Coverage    96.93%   96.93%           
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  Files          318      318           
  Lines        15999    16002    +3     
  Branches      1419     1419           
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+ Hits         15508    15511    +3     
  Misses         349      349           
  Partials       142      142           

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