Store diagnostic hints as a list - #410

## Why
Until now, the state machine view got the receiver's possible and
accepted states from liquidjava-fsm, which re-read the error's
`expected` and `found` predicates as text. The verifier now computes
those states with the SMT solver and reports them on
`StateRefinementError#getContext()` (liquid-java/liquidjava#421). fsm
0.2.0 dropped its error context and only draws diagrams
(liquid-java/liquidjava-fsm#12). This PR switches the view to the
verifier's answer, so the diagram never contradicts the error next to
it.

## What
**Dependencies:** liquidjava-verifier 0.0.36, liquidjava-fsm 0.2.0 and
Spoon 11.5.0, the version the verifier now uses.

**Server**
- `StateRefinementErrorDTO` builds the diagram with
`StateMachineParser.parse(declaration file, context.receiverClass())`,
so a file that declares several classes shows the receiver's class.
- The new `StateMachineDTO` and `StateErrorContextDTO` keep the shape
the webview already reads (`stateMachine.errorContext`). The error
context now has `calledMethod`, `receiver`, `possibleStates`,
`acceptedStates`, `validStates` and `invalidStates`.
- The verifier names each state in every state set. The diagram shows
the first set, and a state is marked so that the marks are never wrong:
- It is **valid** only if the call is accepted in *every* possible
combination with that state.
  - It is **invalid** only if the call is accepted in *none* of them.
- Otherwise it stays unmarked. When the accepted states depend on the
arguments, nothing is marked.
  - With one state set, this gives the same marks as before.

**Client**
- `getStateErrorFocus` uses the server's lists directly. The fallbacks
to `definiteFoundState` and `actualStates` are gone, and so are
`expectedCondition` and `foundCondition`, which nothing displayed.

**Fixed:** the `setHint` test, which broke when hints became a list
(liquid-java/liquidjava#410).

Output for the fsm study fixtures (DatagramSocket and tree node),
serialized by the server:
```json
{"calledMethod":"receive","receiver":"socket","possibleStates":["bound","closed"],"acceptedStates":["unbound","bound","connected"],"validStates":["bound"],"invalidStates":["closed"]}
{"calledMethod":"getFirstChild","receiver":"root","possibleStates":["childrenAllowed"],"acceptedStates":["maybeHasChildren"],"validStates":[],"invalidStates":["childrenAllowed"]}
```
These are the same marks the view showed before for these examples.

## Follow-ups
- One diagram per `@StateSet` (#115, #116,
liquid-java/liquidjava-fsm#8), e.g. ImageWriteParam.
- Send the hints as a list (with their kind) and the error category.
- Cache the diagram per class instead of parsing the file for each
error.

## Tests
- Server: `mvn test`, 27 tests pass, including the new
`StateErrorContextDTOTest`: one state set, several sets with a partly
accepted state, and unknown accepted states.
- Client: `vitest`, 71 tests pass, and `tsc` is clean.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>