Closes #1569.

The repo had no .github/ISSUE_TEMPLATE/ directory, so issue authors hit
an empty form and the bug-report template documented in CONTRIBUTING.md
had no automatic enforcement at filing time.

Adds three YAML issue forms under .github/ISSUE_TEMPLATE/:

- bug_report.yml: title prefix 'bug: ', severity dropdown matching
  CONTRIBUTING.md (Crash / Incorrect output / Misleading error /
  Cosmetic), required fields for ez report output, summary,
  reproduction (.ez snippet), expected, actual, plus optional
  where-to-look and related sections - mirrors the markdown template
  in CONTRIBUTING.md so the form output reads cleanly when triaged.

- feature_request.yml: title prefix 'feat: ', required fields for
  description, use case, alternatives considered, plus an optional
  example section.

- config.yml: disables blank issues and points readers at STANDARD.md
  and CONTRIBUTING.md as the first stop before filing.

All three pass yaml.safe_load.

Co-authored-by: Matt Van Horn <[email protected]>

…unctions, catch struct type mismatches (#1599)

…tion (#1599)

…iltin functions

Adds fallible string-to-type conversions (to_int, to_uint, to_float,
to_bool) returning (T, Error), type-to-string conversions (from_int,
from_uint, from_float, from_bool), and query functions (is_numeric,
is_integer). Panicking versions used for single-var assignment,
_result versions for multi-var destructuring.

…s) (#1603)

Add ez_strconv.c to RT_SRC in Makefile so it's linked into libezrt.a.
Add EzResult_bool include guard to prevent redefinition between ez_io.h
and ez_strconv.h. Register strconv to_X functions in fallible_stdlib and
fallible_type_table so multi-var destructuring works.

Adds pass tests for all 10 strconv functions: basic conversions
(strconv_c.ez, 15 assertions) and multi-var result destructuring
(strconv_result_variants.ez, 10 assertions). Updates TESTING.md
stdlib count from 46 to 48.

Adds optional second parameter (default 10) for specifying conversion
base (2-36). Adds module constants BASE_2, BASE_8, BASE_10, BASE_16,
BASE_36 accessible via strconv.BASE_X or bare via 'using'. Adds
compile-time E5009 error when a literal base outside [2,36] is passed.

Adds pass test for base conversion (11 assertions covering raw int
bases, all 5 constants, default base, and multi-var with base). Adds
fail test for E5009 invalid base compile-time error. Updates TESTING.md
counts (stdlib 49, fail/errors 580).

Adds runtime panic tests for invalid inputs: to_int with non-numeric
string, to_uint with negative, to_float with non-numeric, to_bool with
invalid string, and to_int with invalid base via variable. Also adds
runtime base validation to panicking and result variants of to_int/
to_uint. Updates fail/errors count to 585.

Documents all strconv functions, constants, parameter rules, and
behavior (panic vs error return). Covers valid base range, to_bool
accepted values, to_uint negative rejection, is_numeric/is_integer
semantics, and the single-var vs multi-var destructuring distinction.