074 page filter coverage: Flow PT REST finding

Q Does recipe 003's convert() translate every filter tree stored on a page, and does the server accept what it produces?

Endpoint POST /entity/<type>/_summarize (record_count, api3_hash), one per distinct (type, filters)

Docs claim Silent. The stored tree is the web interface's format.

Actual

3468 query widgets; filters absent or null on 42, a tree on 3426
leaves by (relation, values): is/1 6112, is_not/1 135, in_last/2 9, contains/1 1; in_calendar_*: 0
leaves by path shape: plain 5554, plain on a type the schema no longer has 430, one hop 268,
  one hop through a pivot column (step_0.Task.sg_status_list) 5; two hops or more 0; a summary field 0
entity values by `valid`: valid 3142, parent_entity_token 2722, autocomplete 34, project_token 21,
  absent 19, logged_in_user_token 5
parent_entity_token stored `type`: Entity 1693, Asset 232, Sequence 172, Scene 172, Task 129, ..., "None" 4

recipe 003 convert(), tokens filled (project from Page.project, parent a live row, user FPT_USER_LOGIN):
  trees on a type absent from GET /schema, not sent: 187 over 8 types (disabled since the page was made)
  200 2932 | convert raised 306 | 400 1        distinct (type, filters) sent: 1536
  306x KeyError: "no substitution for token 'parent_entity_token'"   (no row of the parent's type on this site)
    1x 400 "API summarize() Contract.project doesn't exist."   a project filter on a type with no project field
autocomplete, 34 leaves on 17 trees: {"name": "<typed text>", "valid": "autocomplete", "project_ids": [<id>]}

unticked leaves: `active` "true" 5527, true 501, "false" 225, absent 4
  182 trees hold one; counted with it and without it: same 171, different 11, e.g.
  Asset   with 0   without 4     unticked {"path": "project", "relation": "is", "values": [null],
  Version with 0   without 6               "top_level_project_filter": true, "active": "false"}
  Asset   with 0   without 139
empty root group {"logical_operator": "and", "conditions": []} on Shot -> 200, every Shot

Teaches

stored	converts	action
`is`, `is_not`, `contains` with one value	yes	`[path, relation, values[0]]`
`in_last` with `[n, unit]`	yes	`LIST_RELATIONS` keeps the list
a one-hop path, a `step_N` pivot path	yes	send as stored
`active: "false"` on a leaf	yes, and wrongly	drop the leaf: the web interface does not apply an unticked condition
`parent_entity_token`	yes, given the row	its stored `type` is a label (`Entity`, the string `"None"`); send the row's real type
`autocomplete`	no	typed text with no id; refuse the page
a project filter on a type with no `project`	400 `<Type>.project doesn't exist.`	drop `top_level_project_filter` leaves on such a type
a widget whose `entity_type` is no longer in `GET /schema`	not sent	check the type first; the 400 is about the type, not the filter

The only silent failure is the unticked leaf. On a site-level page the project condition is stored unticked with a null value; kept, it narrows to project is null and returns 0 rows at 200. Recipe 003 now drops unticked leaves.
On the probed site no stored tree uses in_calendar_*, a two-hop path or a summary-field path, so the corpus has no evidence for them. Probe 017 enumerates the relations; run one before trusting it.
valid absent on 19 values means a real row, as "valid" does: keep {type, id}.