Add speak-summary skill: text to listenable MP3 via local CPU TTS (#2797)

Adds a skill that converts text, markdown, or the output of another
skill into an MP3 using Kyutai pocket-tts, a small neural TTS model
that runs on CPU.

No existing skill in the collection generates audio, so this fills a
gap rather than duplicating one. It is designed as a terminal step in
a chain: roundup, daily-prep, or meeting-minutes produce the text,
speak-summary makes it listenable.

Two details worth calling out:

- The bulk of SKILL.md is guidance on rewriting written prose for the
  ear before synthesising. Feeding markdown straight into a TTS engine
  produces something technically correct and unlistenable, so that
  step carries most of the value.
- Synthesis is local and CPU-only, so nothing is sent to a cloud
  speech service and the skill works unattended in a headless
  container as well as on a laptop.

The bundled script bootstraps pocket-tts into a cached virtualenv on
first use, selecting a Python in the supported >=3.10,<3.15 range
rather than assuming python3 qualifies, and failing with actionable
guidance when none is available.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 1a70aa08-b622-4825-ad63-5a12370add1f

docs/README.skills.md

@@ -391,6 +391,7 @@ See [CONTRIBUTING.md](../CONTRIBUTING.md#adding-skills) for guidelines on how to
 | [signal-write](../skills/signal-write/SKILL.md)<br />`gh skills install github/awesome-copilot signal-write` | Emit structured agent signals — hands-up, blocked, done, checkpoint, partnership. Signals are written as JSON to .signals/ for dashboard consumption and noted in the journal for persistence. | None |
 | [slang-shader-engineer](../skills/slang-shader-engineer/SKILL.md)<br />`gh skills install github/awesome-copilot slang-shader-engineer` | Use when working with Slang shaders, shader modules, HLSL-compatible GPU code, graphics pipelines, compute shaders, tessellation, ray tracing, parameter blocks, generics, interfaces, capabilities, cross-compilation, shader optimization, shader review, or C++ engine integration for Slang. Trigger on any mention of Slang, .slang files, slangc, SPIR-V from Slang, Slang modules, [shader("compute")], [shader("vertex")], or requests to write/review/refactor shader code with modern language features. Also trigger for Slang-to-HLSL/GLSL/Metal/CUDA cross-compile questions, or when the user says "shader" alongside "generics", "interfaces", "parameter blocks", "autodiff", or "capabilities". | `references/language-reference.md`<br />`references/rules-and-patterns.md`<br />`references/slang-documentation-full.md` |
 | [snowflake-semanticview](../skills/snowflake-semanticview/SKILL.md)<br />`gh skills install github/awesome-copilot snowflake-semanticview` | Create, alter, and validate Snowflake semantic views using Snowflake CLI (snow). Use when asked to build or troubleshoot semantic views/semantic layer definitions with CREATE/ALTER SEMANTIC VIEW, to validate semantic-view DDL against Snowflake via CLI, or to guide Snowflake CLI installation and connection setup. | None |
+| [speak-summary](../skills/speak-summary/SKILL.md)<br />`gh skills install github/awesome-copilot speak-summary` | Convert text, markdown, or a summary produced by another skill into a listenable MP3 using local CPU-only neural text-to-speech. Rewrites written prose for the ear before synthesising. Use when the user asks to "read this out", "turn this into audio", "make an MP3", "I want to listen to this", "podcast version", or wants a spoken digest for a commute or breakfast. | `scripts/tts.sh` |
 | [sponsor-finder](../skills/sponsor-finder/SKILL.md)<br />`gh skills install github/awesome-copilot sponsor-finder` | Find which of a GitHub repository's dependencies are sponsorable via GitHub Sponsors. Uses deps.dev API for dependency resolution across npm, PyPI, Cargo, Go, RubyGems, Maven, and NuGet. Checks npm funding metadata, FUNDING.yml files, and web search. Verifies every link. Shows direct and transitive dependencies with OSSF Scorecard health data. Invoke with /sponsor followed by a GitHub owner/repo (e.g. "/sponsor expressjs/express"). | None |
 | [spring-boot-testing](../skills/spring-boot-testing/SKILL.md)<br />`gh skills install github/awesome-copilot spring-boot-testing` | Expert Spring Boot 4 testing specialist that selects the best Spring Boot testing techniques for your situation with Junit 6 and AssertJ. | `references/assertj-basics.md`<br />`references/assertj-collections.md`<br />`references/context-caching.md`<br />`references/datajpatest.md`<br />`references/instancio.md`<br />`references/mockitobean.md`<br />`references/mockmvc-classic.md`<br />`references/mockmvc-tester.md`<br />`references/restclienttest.md`<br />`references/resttestclient.md`<br />`references/sb4-migration.md`<br />`references/test-slices-overview.md`<br />`references/testcontainers-jdbc.md`<br />`references/webmvctest.md` |
 | [sql-code-review](../skills/sql-code-review/SKILL.md)<br />`gh skills install github/awesome-copilot sql-code-review` | Universal SQL code review assistant that performs comprehensive security, maintainability, and code quality analysis across all SQL databases (MySQL, PostgreSQL, SQL Server, Oracle). Focuses on SQL injection prevention, access control, code standards, and anti-pattern detection. Complements SQL optimization prompt for complete development coverage. | None |