test(acceptance): form filling e2e scenarios

test/acceptance/forms_test.js -- 5 realistic e2e form flows against the PHP
app, valuable for every acting-actor helper, not just Obscura: fill a field
by label + submit + assert the posted value (the generic /form/* POST
handler's print_r($_POST) pattern config_test.js and within_test.js already
rely on for assertions), check a checkbox by its label + state assertion,
select an option + read the selected value back before submitting, a
multi-field form (name + textarea + select) submitted together, and
clear/append behavior on a pre-filled field.

A sixth, negative (required-field/empty-submit) scenario was considered and
dropped: the only fixture with real required="1" attributes
(form/example4.php) depends on a separate local asset server
(127.0.0.1:8100 for its CSS/JS) not available in this environment, and no
other fixture enforces required in a way that's checkable without relying
on native HTML5 validation UI, which headless/synthetic engines don't
reliably surface the same way. Five scenarios matches the mandate's own
"~5-6" range.

Every scenario verified empirically, twice each for consistency, through
the real CLI against all three helpers this environment can actually run:
Obscura (this mandate's own config), Playwright (--grep to bypass tag
filtering, chromium already available), Puppeteer (its config, which has no
grep filtering at all -- runs unconditionally). All 5 passed on all 3, so
all 5 carry @obscura @playwright @puppeteer. WebDriverIO was not touched --
no Selenium server in this environment to verify against, so no @webdriver
tag was added; left for the maintainer to enable and tag once a Selenium
environment is available, per the mandate's own instruction not to tag
what wasn't proven.

No lib/ changes.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: DavertMik

test/acceptance/forms_test.js

@@ -0,0 +1,46 @@
+Feature('Form filling')
+
+Scenario('fill a field by label and submit, then see the posted value @Obscura @Playwright @Puppeteer', ({ I }) => {
+  I.amOnPage('/form/field')
+  I.fillField('Name', 'Alice Example')
+  I.click('Submit')
+  I.see('[name] => Alice Example')
+})
+
+Scenario('check a checkbox by its label and submit @Obscura @Playwright @Puppeteer', ({ I }) => {
+  I.amOnPage('/form/checkbox')
+  I.checkOption('I Agree')
+  I.seeCheckboxIsChecked('#checkin')
+  I.click('Submit')
+  I.see('[terms] => agree')
+})
+
+Scenario('select an option, read the value back, then submit @Obscura @Playwright @Puppeteer', async ({ I }) => {
+  I.amOnPage('/form/select')
+  I.selectOption('Select your age', '13-21')
+  const value = await I.grabValueFrom('#age')
+  I.expectEqual(value, 'teenage')
+  I.click('Submit')
+  I.see('[age] => teenage')
+})
+
+Scenario('fill several fields on a multi-field form and submit @Obscura @Playwright @Puppeteer', ({ I }) => {
+  I.amOnPage('/form/complex')
+  I.fillField('Name', 'Bob Multi')
+  I.fillField('Description', 'a multi-field submission')
+  I.selectOption('Select your age', '21-60')
+  I.click('Submit')
+  I.see('[name] => Bob Multi')
+  I.see('[description] => a multi-field submission')
+  I.see('[age] => adult')
+})
+
+Scenario('clear and append a pre-filled field @Obscura @Playwright @Puppeteer', ({ I }) => {
+  I.amOnPage('/form/field')
+  I.seeInField('#name', 'OLD_VALUE')
+  I.clearField('#name')
+  I.fillField('#name', 'fresh')
+  I.seeInField('#name', 'fresh')
+  I.appendField('#name', '-appended')
+  I.seeInField('#name', 'fresh-appended')
+})