test: fold near-identical test bodies into tables across eight packages - #29463

Folds groups of near-identical test bodies (same parent, same parallel flag, differing only in inputs and expected values) into table-driven tests in eight packages: coderd/templatebuilder, scripts/develop, agent/agentfiles, coderd/x/chatd/chatloop, coderd/x/chatd/chatdebug, enterprise/aibridgeproxyd, cli, and coderd/database/db2sdk. One commit per package.

Every case keeps its previous subtest name, t.Parallel() placement is unchanged, and the set of === RUN names is identical except where standalone TestX_Y funcs became TestX/Y subtests (chatloop: 9 funcs into TestExecuteLocalTools_BatchRuntime; chatdebug: 15 funcs into two tables). Members whose bodies differ in more than data stayed as they were (listed per package in the commit messages). In agent/agentfiles the four TestFuzzyReplace_* funcs were already tables, so the shared request plumbing was hoisted into one helper instead of merging the funcs and losing their per-rule docs. Net -1035 lines across 9 test files; runtime is unchanged (all sub-100ms unit tests).

Validation

• Per package: go test -count=1 -tags=testsmallbatch -parallel=8 ./<pkg>/ -run <regex> -v before and after, with the === RUN name sets diffed
• go test -race -count=2 -shuffle=on on each converted test: pass
• golangci-lint run ./<pkg>/... with a fresh cache: 0 issues in all eight packages
• Repository pre-commit hook (including lint/go) passed on every commit

Part of the test-suite speedup series (see #29457); independent of the other PRs.

Remote validation

Remote run on a dogfood workspace (separate compute), chat https://dogfood.cdr.dev/agents/5bbe73d0-866a-4841-9cc3-c5e5b4d97e44, tested head d7c55d6b0e8 against base 9d973372774: all eight packages pass on the head and under -race -count=3 -shuffle=on; package times are sub-second on both sides (unchanged). === RUN name sets: chatloop 15 to 16 lines with all nine TestExecuteLocalTools_<X> leaves surviving as TestExecuteLocalTools_BatchRuntime/<X>; chatdebug 42 to 44; aibridgeproxyd TestNew 32 to 32, byte-identical sorted list. One correction to the text above: seven chatdebug leaves are renamed, not preserved verbatim (TestRecordingTransport_*UnknownLength* became TestRecordingTransport_UnknownLengthClose/<name without "UnknownLength">), so -run filters keyed on those old names need updating. Endorsed verdict: PASS.

Xum (an AI agent) authored this PR on behalf of @ibetitsmike.