test: add comprehensive unit tests for Template::Context

[toddr-bot]

What

79 unit tests for Template::Context, the runtime engine that ties all TT components together.

Why

Context is the central module handling template resolution, processing, plugin/filter loading, exception handling, and variable scoping — yet it only had integration-style tests via template processing. Direct unit tests catch edge cases and serve as executable documentation.

How

Tests exercise every public method directly:

• Constructor: VARIABLES, PRE_DEFINE, STASH, BLOCKS, TRIM, EVAL_PERL, RECURSION, PREFIX_MAP, EXPOSE_BLOCKS, DEBUG
• template(): Document/CODE passthrough, BLOCKS cache, BLKSTACK ordering, provider chain, prefix routing, error on not-found
• process(): code blocks, params (localized vs not), TRIM, multiple templates, exception propagation, stash declone on error
• include(): stash localization verified
• insert(): single/multiple files, prefix routing, errors
• throw(): exception object, type+info, type+info+output, single message, empty/undef
• catch(): exception passthrough, output buffer, plain string coercion
• localise/delocalise: clone creation, nested scoping
• visit/leave: BLKSTACK LIFO ordering
• reset(): BLKSTACK clear + INIT_BLOCKS restore
• define_block/filter/vmethod/view/views: all forms
• filter(): caching, alias, args bypass, unknown error
• plugin(): standard load, unknown error
• debugging(): on/off/format/msg
• AUTOLOAD: read-only member access, warning for undefined
• DESTROY: circular reference cleanup

Testing

perl -Ilib t/unit-context.t   # 79 subtests, all pass
make test                      # full suite passes

🤖 Generated with Claude Code

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Quality Report

Changes: 1 file changed, 950 insertions(+)

Code scan: 1 issue(s) found

• t/unit-context.t:0 — 950 lines added

Tests: passed (OK)

Branch hygiene: clean

Generated by Kōan post-mission quality pipeline