Make API endpoint validation more strict, improve errors

[bpfoley]

Make API endpoint validation more strict and make the errors messages more helpful.

While here, improve some internal APIs:

1. Add a ApiException::status_code readonly property to reduce boilerplate in derived exceptions
2. Remove $query_params from all handler functions that don't have params.
3. Add ApiException::fromException to reduce boilerplate when converting exceptions

Sandbox: https://www.pgdp.org/~cpeel/c.branch/method-err/

[cpeel]

These are great improvements, Brian!

Before:

export API_KEY=review
curl -H "Accept: application/json" -H "X-API-KEY: $API_KEY" \
     -X GET "https://www.pgdp.org/api/v1/stats/site?blah=1"
{
    "server_time": "2026-06-04T18:15:37+00:00",
    "registered_users": 893,
    "active_users_1_day": 1,
    "active_users_7_day": 8,
    "active_users_30_day": 15
}

After:

export API_KEY=review
curl -H "Accept: application/json" -H "X-API-KEY: $API_KEY" \
     -X GET "https://www.pgdp.org/~cpeel/c.branch/method-err/api/v1/stats/site?blah=1"
{
    "error": "API endpoint /v1/stats/site takes no query parameters, but was called with blah",
    "code": 12
}

[bpfoley]

Reproducers:

API_KEY=revoew
ROOT=https://www.pgdp.org/~bfoley/c.branch/method-err

# API endpoint v1/queues: Method WIBBLE not supported. Valid methods: GET
curl -i -X WIBBLE "$ROOT/api/v1/queues?roundid=P3&show=populated" \
    -H "Accept: application/json" \
    -H "X-API-KEY: $API_KEY"

# 1. API endpoint /v1 has no part projectz. Valid child parts: documents, dictionaries, projects, queues, stats, storage.
curl -i -X GET "$ROOT/api/v1/projectz/projectID5e263d080c3f4/wordcheck/ai" \
    -H "Accept: application/json" \
    -H "X-API-KEY: $API_KEY"

# 2. No children:
# API endpoint /v1/projects/projectID5e263d080c3f4/wordcheck has no part ai
curl -i -X GET "$ROOT/api/v1/projects/projectID5e263d080c3f4/wordcheck/ai" \
    -H "Accept: application/json" \
    -H "X-API-KEY: $API_KEY"

# 3. Missing part.
# API endpoint /v1/stats is missing a part. Valid child parts: site, user.
curl -i -X GET "$ROOT/api/v1/stats" \
    -H "Accept: application/json" \
    -H "X-API-KEY: $API_KEY"

# Invalid project state wibble. Valid states: ...
curl -i -X PUT "$ROOT/api/v1/projects/projectID5e263d080c3f4/checkout?state=wibble" \
    -H "Accept: application/json" \
    -H "X-API-KEY: $API_KEY"

# Invalid page state wibble. Valid states: ...
curl -i -X PUT "$ROOT/api/v1/projects/projectID5e263d080c3f4/pages/042.png?state=F1.proj_avail&pagestate=wibble" \
    -H "Accept: application/json" \
    -H "X-API-KEY: $API_KEY"

# API endpoint /v1/dictionaries takes no query parameters, but was called with param1, param2
curl -i -X GET "$ROOT/api/v1/dictionaries?param1=invalid&param2" \
    -H "Accept: application/json" \
    -H "X-API-KEY: $API_KEY"

# Duplicate field[] args: title
curl -i -X GET "$ROOT/api/v1/projects?per_page=1&page=1&state=P3.proj_avail&field[]=title&field[]=title" \
    -H "Accept: application/json" \
    -H "X-API-KEY: $API_KEY"

# Check ApiException::fromException works using a deleted project
# try { ... } catch (NoProjectPageTable $exception) {
#     throw NotFoundError::fromException($exception);
# }
curl -i -X GET "$ROOT/api/v1/projects/projectID69668cd98b3b3/pages" \
    -H "Accept: application/json" \
    -H "X-API-KEY: $API_KEY"