Add note explaining OpenAI's developer role usage for reasoning models
and compatibility issues with OpenAI-compatible endpoints that return
"Incorrect role information" errors. Include configuration example for
custom models with reasoning=true.

Add SPDX headers to all source files, license texts, and sidecar files
for REUSE.software compliance. Rewrite README with badges, better
description, and usage examples. Minor capitalization fix in CLI help
(rumilo → Rúmilo).

Change 'Current time:' to 'Current date/time:' in prompt templates to
accurately reflect that currentTime includes both date and time
information.

- Note context-aware prompt building in control flow
- Add System Prompts section documenting builder functions
- Update pre-fetch injection to reflect tags

Convert static system prompt strings to builder functions that accept
runtime context (current time, git history availability).

- Replace Markdown sections with XML-style tags (approach, answering,
environment)
- Add librarian persona to repo mode, field researcher to web mode
- Make git history guidance conditional on full vs shallow clone
- Remove duplicative tool descriptions that restated tool schemas
- Repo prompt now prioritises agent instruction files for orientation
- Web prompt no longer assumes SERP-then-fetch workflow
- Pre-fetch injection uses XML tags instead of raw
string concatenation

- More descriptive error messages with examples for invalid model format
  and missing config
- Clearer, more consistent tool descriptions across all agent tools
- Comprehensive help text with version, commands, usage, options, and
  config sections
- Add commit.gpgsign=false to test setups to prevent GPG signing issues
- Minor formatting consistency (e.g., 'KB' without space)

Remove private flag and add publishing metadata: description, license,
files whitelist, and prepublishOnly build script.

Migrate from @mariozechner/pi-agent to @mariozechner/pi-agent-core
v0.52.8, alongside pi-ai v0.52.8 which adds AWS Bedrock support.

Security improvements for workspace sandboxing:
- Remove tilde expansion from expandPath() to prevent homedir escape
- Add symlink traversal detection in ensureWorkspacePath()
- Filesystem tools (read, grep, ls, find) now enforce containment

New features for custom model configuration:
- api_key field with env var, $VAR, ${VAR}, and !shell command
  resolution
- Optional custom headers support with same value resolution

Other changes:
- Add comprehensive test suite (bun test)
- Improve workspace cleanup on clone/checkout failures
- Update AGENTS.md and README.md documentation