fix(workflows): apply chained expression filters left-to-right

[Noor-ul-ain001]

Summary

Filter chaining is broken in the workflow expression evaluator. _evaluate_simple_expression splits at the first top-level | and treats the entire remainder as one filter, so any expression with more than one filter raises ValueError.

This makes the canonical map use case impossible: map returns a list, and join is the only filter that renders a list to a string — the two are meant to be chained.

from specify_cli.workflows.expressions import evaluate_expression
from specify_cli.workflows.base import StepContext

ctx = StepContext(inputs={"rows": [{"name": "a"}, {"name": "b"}]})

# want "a, b"; actual: ValueError: filter 'join' used in an unsupported form
evaluate_expression("{{ inputs.rows | map('name') | join(', ') }}", ctx)

A single filter (| map('name') or | join(', ') alone) works, so chaining is the only broken axis — but it affects every registered filter.

Root cause

pipe_idx = _find_top_level(expr, "|")
if pipe_idx != -1:
    value = _evaluate_simple_expression(expr[:pipe_idx].strip(), namespace)
    filter_expr = expr[pipe_idx + 1:].strip()   # <- whole tail, incl. later `|`
    ...
    filter_match = re.match(r"(\w+)\((.+)\)", filter_expr)  # chokes on the next `|`

For map('name') | join(', '), filter_expr becomes the full string and the greedy (.+) argument capture spans the second filter, so parsing fails.

Fix

• Split the pipe chain into top-level segments (quote/bracket aware, so a literal | inside a quoted argument such as join(' | ') or an operand like 'a|b' is not treated as a separator).
• Fold each filter over the running value left-to-right.
• The single-filter logic is extracted verbatim into a new _apply_filter helper, so all existing strict handling is preserved and now applies to every link in the chain:
  • from_json arity/trailing-token strictness
  • "registered filter used in an unsupported form" vs "unknown filter" messages

Tests

Added to TestExpressions:

• test_chained_filters_apply_left_to_right — map → join, a three-link map → join → contains, and default → contains.
• test_chained_filter_error_in_later_link_raises — a mis-wired filter anywhere in the chain still fails loudly.
• test_pipe_in_quoted_arg_is_not_a_filter_separator — literal | inside quotes stays intact.

Test-the-test verified: the two chaining tests fail without the source change and pass with it. Full TestExpressions (37 tests) passes; the only failures in tests/test_workflows.py are the pre-existing Windows symlink-guard tests (unrelated, require elevation).

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