Reject bad operator input before the test runs

Operator entries used to be checked differently by the kiosk, the web console and the terminal, and a serial the server would refuse was only caught at upload, after the test had already run.

• Added: every submission is now judged by the station itself; a rejected entry keeps the form open with a plain-language message under the field (“Remove the space (character 3) — allowed: uppercase letters, digits, -”, “Must be exactly 4 digits — you typed 2”), and the raw pattern is never shown to the operator
• Added: prefix and suffix on unit fields and text inputs, displayed locked around the input and composed into the recorded value, so the operator scans only the variable part and pattern never has to repeat the fixed one
• Added: pattern_message for patterns that cannot explain themselves; patterns now match the whole entry (SN-[0-9]+ rejects SCRAP SN-0042 XX, anchors optional), and serial, part, revision and batch fields default to the server's allowed characters so a bad scan fails at the form, not at upload
• Improved: one shared form for phase prompts and unit identification with keyboard-first flow, Ctrl/⌘+Enter submit and password managers suppressed; the Studio editor refuses a pattern the station cannot compile while you type, nudges you to add a message when one cannot be derived, and screen previews use the exact verdict a run would give
• Fixed: “Run again” no longer crashes when the unit config changed between two runs; the docs for text inputs and unit under test cover the new fields (Studio desktop keeps the previous client-side checks for now)