oh-my-pi/packages/utils/CHANGELOG.md

Changelog

[Unreleased]

Fixed

• Fixed the Markdown renderer incorrectly breaking into a raw code block when a 4-space-indented line (such as a box-drawing tree child under a └── branch) directly followed paragraph text; it now correctly stays part of the paragraph, matching standard Markdown behavior.

[17.3.2] - 2026-08-13

Fixed

• Fixed fetchWithRetry() aborts during retry backoff to preserve the documented "Request was aborted" error contract (#8450).

[17.3.0] - 2026-08-13

Fixed

• Optimized performance of partial JSON parsing for long streaming tool-call arguments.
• Fixed Mermaid ASCII multi-word edge labels where routed lines would show through spaces.

[17.2.15] - 2026-08-12

Changed

• Extended parsed Server-Sent Events (SSE) to include optional id and retry fields, enabling reconnecting transports to retain stream cursors and respect server-requested retry intervals.

[17.2.13] - 2026-08-11

Changed

• Changed stale process-log retention from the newest five files globally to one newest file per completed process and day within the current and previous four local calendar days. This preserves bounded daily diagnostic coverage while continuing to remove one-use audit files.
• Changed outbound User-Agent consumers to share the versioned USER_AGENT constant (omp/<version>).

Fixed

• Fixed Mermaid ASCII state pseudostates rendering empty boxes, miscoloring final-state borders, and inverting rounded corners in bottom-to-top diagrams.

[17.2.11] - 2026-08-07

Added

• Added repair and rawKeys options to parseFrontmatter to support spec-conformant loading (disabling lenient recovery and preserving keys verbatim), and exported normalizeFrontmatterKeys for manual key normalization.

Fixed

• Fixed the in-house marked list tokenizer incorrectly consuming trailing blank lines at the end of input, ensuring correct list tightness and token generation matching standard marked behavior.

[17.2.10] - 2026-08-06

Added

• Introduced zero-dependency in-house modules replacing external packages, importable via @oh-my-pi/pi-utils/<module>: acp (Agent Client Protocol), browsers (Chrome for Testing discovery/install), chalk (ANSI styling), dates (date formatting), dom (HTML parser, WHATWG DOM subset, and CSS selectors), docx (DOCX to HTML), headers (browser header generation), lru (LRU cache), marked (GFM markdown lexer/parser), readability (article extraction), template (Handlebars-compatible templating), turndown (HTML to Markdown), vterm (headless terminal emulator), and xml (XML parser).
• Added postmortem fatal recovery hint providers to allow applications to print actionable recovery commands before cleanup starts.

Changed

• Rewrote the logger file backend in-house, maintaining the identical line format, daily rotation, and pruning behavior without external dependencies.

Fixed

• Fixed PowerShell (powershell.exe / pwsh) support when used as a custom shellPath by correctly passing -NoLogo -Command (and -NoProfile under PI_BASH_NO_LOGIN) instead of POSIX flags.
• Fixed the in-house marked list tokenizer consuming the trailing blank line into the list token when the next top-level line was a plain paragraph. The blank now always becomes a separate space token (matching real marked), so a list's token shape no longer depends on what follows it — restoring the TUI streaming lexer's freeze invariant — and a list followed by a paragraph is tight, not loose, per CommonMark.
• Added the missing Handlebars built-in lookup helper to the in-house template engine ({{lookup obj key}}, proto-safe property access; a user-registered lookup helper still takes precedence).

Removed

• Removed external dependencies on handlebars, winston, and winston-daily-rotate-file.

[17.2.9] - 2026-08-05

Added

• Added a public compareVersions utility (@oh-my-pi/pi-utils) that compares two version strings with SemVer-2.0 prerelease ordering, build-metadata stripping, and numeric segment comparison without float overflow; never throws.

Fixed

• Honor the current process PATH when caching executable lookups, preventing stale tool paths after environment reloads.
• Parsed account-cap reset windows such as “Your limit will reset in 13 minutes” so credential backoff honors the provider's full reset duration.

[17.2.6] - 2026-08-03

Added

• Added a shared file-lock utility backed by process-owned native OS locks with automatic crash release and bounded asynchronous retry.

[17.2.5] - 2026-08-03

Added

• Added utility functions parseFlag(), getBrowserRelayDir(), and getGlobalDaemonRuntimeDir() to support browser relay mode and global daemon runtime directory resolution.

Changed

• Updated the lightweight CLI runner to support static command metadata, allowing root help to render without importing full command implementations.

[17.2.4] - 2026-08-01

Added

• Added getSecretPlaceholderKeyPath(), getDaemonRuntimeDir(), getProviderInFlightRoot(), and getMarketplacesRegistryPath() to resolve secret key, daemon runtime, provider in-flight, and marketplace registry paths under their respective XDG categories (state, data) instead of the config root.
• Existing installs enabling XDG keep their data: a legacy ~/.omp/agent/secret-placeholder.key or ~/.omp/marketplaces.json is copied to its XDG location on first resolution, so persisted transcripts still deobfuscate and added marketplaces survive the move.

Changed

• Headless hosts (print/RPC/ACP/eval/SDK) now use a 1s SQLite busy_timeout for the session-critical databases (agent.db, history.db, stats.db) via getDbBusyTimeoutMs(), so lock contention no longer freezes the protocol loop for the full interactive 5s timeout; interactive hosts keep the 5s timeout.

Fixed

• Fixed Bun test-runtime detection treating application-owned NODE_ENV=test and BUN_ENV=test values as test-runner signals (#7261).

[17.2.1] - 2026-07-30

Added

• Added a postmortem.quit configuration option to safely handle shutdown paths when the terminal output has already disconnected.
• Added project-keyed OMP security-state directory helpers under the user state root.

[17.1.8] - 2026-07-28

Added

• Added setProcessName utility to set the OS-visible process name on Linux via bun:ffi, bypassing Bun's process.title limitations.

Fixed

• Fixed child shell environment filtering to drop launch-directory .env values in addition to Bun-autoloaded .env.local values.

[17.1.5] - 2026-07-27

Fixed

• getShellConfig no longer throws No bash shell found on Windows hosts without a discoverable bash. resolveWindowsShell searches Git for Windows install roots (machine, per-user, GIT_INSTALL_ROOT, scoop app dirs — scoop shims sh.exe/git.exe but never bash.exe), then bash.exe/sh.exe on PATH, and finally falls back to cmd.exe from ComSpec with /c args, so shell resolution always succeeds.

[17.1.4] - 2026-07-26

Fixed

• Fixed postmortem signal and fatal shutdown exits being intercepted by temporary process.exit guards during extension startup (#6488).
• Corrected Windows shell resolution errors to identify the active global, project, overlay, or runtime source for shellPath instead of directing every user to the retired settings.json file (#6579).
• Contained timed-out child lifecycle rejections so ptree callers cannot leak an unhandled TimeoutError after settling (#6635).
• Fixed an invalid configured shellPath being silently masked whenever an earlier caller had already resolved a shell in the same process; the guidance error now surfaces regardless of cache state.

[17.0.9] - 2026-07-23

Breaking Changes

• Renamed getAutoQaDbDir to getAutoQaDbPath for accuracy; update any usage accordingly

[17.0.5] - 2026-07-18

Changed

• Updated installRuntimeModuleResolver to return an uninstaller function that restores the stock node:module resolver once all runtime roots are unregistered.
• Added documentation regarding a known limitation with Bun 1.3.14's createRequire behavior when the module resolver patch is active.

[17.0.2] - 2026-07-17

Added

• Added a structured log sink API (registerLogSink, LogEvent, LogLevel) to the centralized logger, enabling out-of-band consumers (such as OpenTelemetry) to receive log events without affecting local file or console logging.

Changed

• Bounded default ptree.ChildProcess stderr retention to a 32 KiB tail to prevent memory leaks in long-lived subprocesses. Full stderr capture must now be explicitly requested at spawn time using { stderr: "full" } on spawn or exec.

Fixed

• Fixed fatal cleanup failing to reach process.exit() when terminal stderr is revoked.
• Isolated rotating log files and audit state per process to prevent concurrent instances from racing during compression and rotation.

[17.0.1] - 2026-07-16

Fixed

• Added scoped graceful handling for stdio-write EPIPE rejections so protocol servers can await postmortem cleanup when their peer disconnects (#4788).

[17.0.0] - 2026-07-15

Fixed

• Improved SSE streaming performance by batching complete lines into a single UTF-8 decode per chunk, reducing decoder overhead.
• Fixed an issue in parseFrontmatter where a single malformed YAML line would corrupt sibling values by parsing each line independently.

[16.5.2] - 2026-07-14

Fixed

• Improved CLI argument and flag validation error output to display a concise error message and command usage instead of a minified code frame.
• Corrected required variadic positionals to render as MODELS... instead of [MODELS] in usage help.

[16.5.1] - 2026-07-14

Added

• Added terminal stderr guard utilities (suppressTerminalStderr and restoreTerminalStderr) to prevent macOS runtime diagnostics from corrupting TUI viewports while ensuring crash reports remain visible.

Fixed

• Fixed an issue in Mermaid ASCII routing where unreachable edge attachment points caused unbounded pathfinder searches.

[16.4.6] - 2026-07-12

Added

• Added AsyncDrain, the deferred write-batching helper previously private to the coding-agent's prompt-history storage; now shared with model-perf recording.

[16.4.2] - 2026-07-10

Added

• Added stringifyJson utility with support for BigInt serialization.

[16.3.12] - 2026-07-08

Added

• Added postmortem.interceptUnhandledRejections() to register interceptors consulted before an unhandled rejection tears the process down; a consuming interceptor (e.g. the JS eval runtime claiming rejections floated by user cell code) keeps the process alive and owns reporting.

Fixed

• Fixed child shell environment filtering to drop launch-directory .env.local values that Bun auto-loaded before OMP starts command shells. (#4723)

[16.3.10] - 2026-07-06

Added

• Added postmortem.markExpectedCleanupError() / postmortem.isExpectedCleanupError() to tag errors thrown by routine resource teardown; the global uncaughtException/unhandledRejection handlers downgrade marked errors (walking the cause chain) to warnings instead of exiting the process.

Fixed

• Bounded postmortem cleanup with a 10s deadline so a hanging cleanup callback can no longer wedge the process indefinitely after a fatal error or signal; the process now always reaches process.exit.

[16.3.7] - 2026-07-05

Added

• Added classifyJsonPrefix, a strict RFC 8259 streaming-buffer classifier ("complete" | "prefix" | "invalid"). Providers use it to disambiguate identifierless streaming tool-call deltas: a {-prefixed chunk only advances to a sibling call when the current argument buffer cannot absorb it.

[16.3.1] - 2026-07-02

Fixed

• Fixed parseJsonWithRepair failing tool calls whose streamed arguments contain an unquoted string value (e.g. {"paths": packages/foo/*, "i": "…"}). Final parsing now recovers such barewords in object/array value position as strings, terminating at , / } / ] / newline. Recovery deliberately refuses anything that could mask real structure or bad data — truncated values, tokens containing " / { / [ or a key-like : (URL :// and Windows :\ colons stay literal), and non-finite atoms (NaN, Infinity, undefined) — and streaming partial parses still roll back unfinished barewords instead of committing them.

[16.3.0] - 2026-07-02

Added

• Added wrapFetchForExtraCa and withExtraCaFetch utility functions to apply NODE_EXTRA_CA_CERTS to Bun's RequestInit.tls.ca configuration.

[16.2.9] - 2026-06-30

Added

• Improved resilience in fetchWithRetry() by adding a response-body retry gate to handle deterministic provider failures that return retryable HTTP statuses.

Fixed

• Fixed YAML frontmatter parsing for skill descriptions containing unquoted colons (: ), ensuring typed fields are correctly preserved without triggering unnecessary warnings.

[16.2.7] - 2026-06-30

Added

• Added a utility to detect binary files based on content sniffing.

[16.2.6] - 2026-06-29

Added

• Added stripWindowsExtendedLengthPathPrefix() utility to normalize \\?\ and native Win32 path prefixes before Bun import or spawn calls.

[16.2.3] - 2026-06-28

Added

• Added escapeXmlAttribute utility function for safe XML attribute value encoding.

Fixed

• Fixed a crash in ptree.ChildProcess.bytes() and the ssh:// read path when handling large subprocess outputs (over 128 KB) under Bun by ensuring it consistently returns a Uint8Array.

[16.2.0] - 2026-06-27

Added

• Added a relaxed JSON parser supporting single-quoted strings, unquoted keys, and comments.
• Added parseStreamingJson and parseStreamingJsonThrottled for robust, efficient parsing of truncated or incremental streaming JSON.
• Added an XDG-aware document conversion cache directory helper.
• Exported removeWithRetries() as a standalone asynchronous function to handle retry-on-EBUSY cleanup logic.

Changed

• Improved readSseJson to gracefully recover truncated or malformed final events using the streaming JSON parser, ending the stream cleanly instead of throwing.
• Increased the retry delay for EBUSY file-lock errors from 25ms to 50ms (extending the total retry window to 2 seconds) to improve reliability on Windows.

[16.1.8] - 2026-06-20

Added

• Exported removeSyncWithRetries() as a standalone function so tests that manage their own temp dirs can use the same retry-on-EBUSY cleanup logic as TempDir.removeSync().

[16.1.3] - 2026-06-19

Changed

• Expanded the TempDir Windows retry window from 4×10ms to 40×25ms (1s total) to accommodate SQLite WAL/SHM file handle release delays

Fixed

• Made EPIPE rejections from IPC send() to worker subprocesses (syscall: "send") non-fatal: the global unhandledRejection handler now logs and continues instead of terminating the session when an optional subsystem's pipe breaks. A broken optional subsystem (TTS/STT/tiny-title/MCP) can no longer crash the whole agent session mid-task. (#2997)

[16.1.2] - 2026-06-19

Added

• Added directoryExists(dir) to dirs: resolves whether a path is an existing directory, returning false on any stat failure (ENOENT, permission, non-directory). Lets callers check a directory is safe to chdir into before setProjectDir throws.

Removed

• Removed the public createAbortableStream API from @oh-my-pi/pi-utils. Consumers should use the lighter, direct-reader abortableSource async generator inside @oh-my-pi/pi-utils/stream to avoid the extra ReadableStream wrapper layer and per-chunk enqueue overhead.

[16.0.11] - 2026-06-19

Removed

• Removed getIndentation, setDefaultTabWidth, and getDefaultTabWidth helpers

[16.0.8] - 2026-06-18

Changed

• Mermaid diagrams are now rendered to ASCII by a first-party vendored renderer (src/vendor/mermaid-ascii, derived from the MIT-licensed beautiful-mermaid, ASCII pipeline only) with terminal display width measured via Bun.stringWidth (grapheme-aware, correct for wide/East-Asian glyphs and emoji). Inline label formatting (HTML formatting tags and markdown emphasis) is now reduced to plain text instead of printed raw.

Removed

• Removed the external beautiful-mermaid dependency (and its transitive elkjs, ~3.13MB) in favor of the vendored ASCII renderer.

[16.0.3] - 2026-06-16

Added

• Added escapeXmlText utility to escape XML-significant characters &, <, and > in element body text
• Added isTerminalHeadless() / setTerminalHeadless() to centrally suppress real-terminal side effects (stdout escape/frame writes, stdin raw mode, CSI/OSC capability probes, SIGWINCH, window-title changes, emergency restore) under the test runtime. Defaults on when bun test sets NODE_ENV=test; terminal-contract tests opt out via setTerminalHeadless(false)

[15.13.3] - 2026-06-15

Added

• Added installWorkerInbox(port) / consumeWorkerInbox() to @oh-my-pi/pi-utils/worker-host. A self-dispatching CLI host that imports a Bun worker module dynamically attaches the worker's real message listener after Bun flushes the messages the parent posted before spawn, dropping a synchronously-posted init. The host installs this buffering inbox synchronously in the entry's sync prefix so a listener exists at flush time; the worker module consumes it and binds the real handler, replaying anything buffered.

[15.13.1] - 2026-06-15

Added

• Added profile-aware directory helpers and isolated profile state roots, while keeping the install ID shared across profiles.
• Added a named-profile API to the dirs module — setProfile(), getActiveProfile(), getProfileRootDir(), and normalizeProfileName() — plus resolveProfileEnv(), which selects the active profile from OMP_PROFILE (canonical; takes precedence) then PI_PROFILE (legacy fallback, consulted only when OMP_PROFILE is unset).
• Added support for a runtime overrides map in RuntimeInstallSpec, which is now written into generated runtime package.json manifests to force dependency pins (including transitive ones) across the runtime tree
• Added a lightweight loop-phase breadcrumb stack (pushLoopPhase/popLoopPhase/currentLoopPhase, plus takeRecentLoopPhase which returns the live phase or the most recently popped one and clears it) so the TUI event-loop watchdog can attribute a main-thread block to the phase that caused it — including a synchronous phase already popped before the watchdog's delayed tick runs (#2485)
• Added FetchWithRetryOptions.timeout (forwarded to the underlying fetch call). false disables Bun's native ~300s pre-response timeout; a positive number overrides the ceiling. Bare browser/Node fetch ignores it (#2422)
• Added the side-effect-free @oh-my-pi/pi-utils/worker-host module (declareWorkerHostEntry() / workerHostEntry()), extracted from env (still re-exported there) so worker spawn sites can resolve the self-dispatching CLI host entry without importing env's side-effecting module graph.

Fixed

• Fixed profile directory isolation when a profile's agent .env customizes directory roots: directory-affecting keys (XDG_DATA_HOME/XDG_STATE_HOME/XDG_CACHE_HOME, and a default-mode PI_CODING_AGENT_DIR) are now honored. The env loader rebuilds the dirs resolver after applying .env files (refreshDirsFromEnv()), so a profile .env that points XDG roots elsewhere no longer leaks state into the home-based config dir.
• Made TempDir cleanup retry transient Windows EBUSY/EPERM/ENOTEMPTY removal failures so tests are less likely to fail when deleting just-used temp directories.
• Fixed installRuntimeModuleResolver() to keep bare requests from runtime-cache modules inside that registered runtime before falling back to host/workspace packages.

[15.12.4] - 2026-06-13

Fixed

• Fixed abortable stream wrappers to cancel the source stream on abort, so timeout watchdogs release upstream HTTP bodies instead of only stopping the local reader.

[15.12.0] - 2026-06-12

Added

• Added runtime-install: shared on-demand runtime dependency support — ensureRuntimeInstalled() (locked, idempotent bun install of a pinned dependency set into a cache dir) and a multi-root installRuntimeModuleResolver()/resolveRuntimeModule() for loading those graphs inside compiled binaries (Bun #1763). Extracted from the coding-agent tiny-model worker; now also backs Mnemopi's on-demand fastembed runtime (#2389)
• Added getFastembedRuntimeDir() (~/.omp/cache/fastembed-runtime) alongside getFastembedCacheDir()

[15.11.4] - 2026-06-12

Added

• Added getEditorConfigFormatting(file): returns the .editorconfig-pinned tabSize/insertSpaces (both optional, no fallback) so LSP-format callers can layer per-file defaults under it without paving over silence with the renderer's display tab width (#2329).

[15.11.3] - 2026-06-11

Added

• Added getEditorConfigFormatting(file): returns the .editorconfig-pinned tabSize/insertSpaces (both optional, no fallback) so LSP-format callers can layer per-file defaults under it without paving over silence with the renderer's display tab width (#2329).

[15.11.1] - 2026-06-11

Fixed

• Fixed cleanup reentry noise during fatal shutdown: recursive cleanup requests now no-op idempotently instead of logging repeated Cleanup invoked recursively errors (#2284).

[15.11.0] - 2026-06-10

Added

• Added the path-tree module (buildPathTree, walkPathTree, formatGroupedPaths, isUrlLikePath), moved from the coding agent's grouped file output so compaction file lists can share the same prefix-folded directory-tree rendering; formatGroupedPaths gains an optional annotate callback for per-file suffixes

Fixed

• Fixed the {{join}} prompt helper joining with a literal two-character \n when templates pass "\n" as the separator — Handlebars string literals carry no escape processing. The separator now unescapes \n/\t, matching the {{#list}} helper's documented convention (visible as literal \n between paths in compaction <read-files> lists).

[15.10.11] - 2026-06-10

Added

• Restored PI_DEBUG_STARTUP streaming startup markers: logger.time now writes a synchronous [startup] <op>:start / :done / :fail stderr line per phase (independent of PI_TIMING), so a startup that hangs hard still names the phase it is stuck in — the PI_TIMING tree only prints after startup completes and is structurally unable to diagnose a hang. The CLI runner emits cli:load:<name> markers around each lazily-imported command module for the same reason.
• Added logger.openSpanPath(): ops of the currently-open timing-span chain (root → deepest), used by the coding agent's startup watchdog to name the in-flight phase of a stalled startup.
• Added declareWorkerHostEntry() / workerHostEntry() (env): self-dispatching CLI entrypoints declare Bun.main as the worker host so worker spawn sites can re-enter the single entry module with WorkerOptions.argv selectors across source, npm-bundle, and compiled distributions

Changed

• Changed prompt.compile() to cache compiled templates by the raw template string so repeated calls reuse the same compiled function without re-disambiguating
• Snowflake.formatParts packs the id as a single 64-bit BigInt hex format instead of stitching four 16-bit segments (simpler and ~1.7x faster), and getTimestamp extracts via exact double arithmetic instead of a BigInt round-trip. Output is bit-identical.
• Logger initialization is lazy: the winston logger, file transport, and log-directory creation now happen on first log emission instead of at module import (the import previously cost ~8ms of fs work on the CLI startup path); the in-memory timing infrastructure never touches winston
• prompt.format() post-processing got cheap per-line guards and a single-pass ASCII-symbol replacement (was 7 chained regex passes per line), roughly halving render post-processing cost; output is byte-identical

Fixed

• Fixed prompt.format() so ASCII symbol replacements such as --> and != still run on lines containing a closing HTML comment token when not inside a comment
• isCompiledBinary() now also honors a define-folded process.env.PI_COMPILED (only Bun.env was checked), so builds that constant-fold process.env keep compiled-binary detection without relying on import.meta.url bunfs markers
• omp <cmd> --help now loads only the requested command module instead of the entire command table, so an unrelated command whose import graph hangs or crashes can no longer take down every per-command help invocation.

[15.10.8] - 2026-06-09

Removed

• Removed the exported hookFetch API, which previously intercepted globalThis.fetch via middleware handlers
• Removed hookFetch from the package entrypoint, so imports from @.../utils no longer provide this fetch interception helper

[15.10.0] - 2026-06-06

Changed

• logger.printTimings() (the PI_TIMING startup tree) now surfaces two previously-invisible regions: a (before instrumentation) line for runtime init / uncaptured pre-marker work, and an (unattributed self) line for the root span's own untimed work so the gap between visible top-level spans and Total is no longer swallowed. Total is now labelled (since first marker) to make the window explicit. The restored module-timer.ts preload can feed module spans into the report: each module records onLoad → final top-level marker as total, a prepended body marker → final marker as body/TLA, and resolved static imports as a bounded dependency tree so the report separates graph wait from actual top-level module work.

[15.9.2] - 2026-06-05

Added

• Added getAuthBrokerSnapshotCachePath() with OMP_AUTH_BROKER_SNAPSHOT_CACHE override support for isolating the encrypted broker snapshot cache.

[15.9.1] - 2026-06-04

Fixed

• Hardened getIndentation against malformed paths: any filesystem error from the .editorconfig probe (e.g. ENAMETOOLONG on oversized garbage path segments) is now swallowed and cached as a miss instead of escaping and crashing the TUI mid-render (#1871).
• Fixed getIndentation (and the edit renderer's replaceTabs callers) crashing with ENAMETOOLONG/ENOTDIR/etc. when handed a path with an overlong component or a non-directory in its parent chain. Editorconfig discovery now short-circuits to the default tab width on any path component above NAME_MAX (255 bytes) and absorbs any FsError while walking the editorconfig chain — best-effort discovery must never escape as an uncaught exception (#1872).

[15.9.0] - 2026-06-04

Added

• Added color helpers colorLuma (perceptual luma), relativeLuminance (WCAG, linearized sRGB), and hslToHex to the color utilities. The luminance helpers parse #rgb/#rrggbb hex and 256-color palette indices, returning undefined for unparseable values.
• Added peekFileEnds, a single-open head-and-tail file peek helper that reuses the head bytes for the tail when the file fits the head window.
• Added peekFileTail, the tail mirror of peekFile: reads up to the last maxBytes of a file ending at EOF, reusing the same pooled-buffer strategy (no per-call allocation for small reads).

[15.7.3] - 2026-05-31

Added

• Added getFastembedCacheDir to return the FastEmbed model cache directory under ~/.omp/cache/fastembed

Fixed

• Fixed $flag environment parsing to accept lowercase truthy values such as y, true, yes, and on

[15.6.0] - 2026-05-30

Added

• Added an XDG-aware tiny-title model cache directory helper for coding-agent local title models.