feat: initial text-extract v0.1.0 (text.extract@0.1.0)

First real F∆I capability module. Ships as alpha in the store
index — installable, but layout-naive PDF extraction. Bumps to
1.0.0 require either the planned service-mode variant
(host-services-backed pdfium/mupdf) or confirmed-good
extraction quality on a representative document set.

Capability surface:

  Inputs:   document : bytes  (PDF or DOCX)
  Outputs:  extracted : json  (ExtractedDocument)
  Permissions: none — pure in-WASM, no filesystem, no network

Output schema:

  {
    "engine": "pdf-extract" | "zip+quick-xml",
    "engine_version": "<version>",
    "pages": [{ "number": <u32>, "text": <string>,
                "confidence?": <f64>, "bbox?": {x,y,w,h} }]
  }

The optional confidence and bbox fields are reserved for the
future service-mode variant. The host-services infrastructure
that backs pdfium/mupdf does not exist yet (Phase 0.5+); when
it lands, text-extract v0.2.0 will populate these fields without
an API break.

Engines:

  PDF:  pdf-extract 0.7 (pure Rust, MIT-licensed). Single-column
        documents extract reliably. Multi-column or table-heavy
        layouts may produce reordered text — documented in
        README as a known limitation of the in-WASM v0.1.0 path.

  DOCX: ad-hoc parser using the zip and quick-xml crates. Walks
        word/document.xml, concatenates run-level text, inserts a
        newline at each paragraph boundary. Tables, footnotes,
        and embedded objects are not extracted in v0.1.0.

The module is the first reference user of fai-module-sdk. The
public surface is one #[fai_module] function — no wit_bindgen,
no Guest impl, no allow attributes. Testing surface is the same
function via crate-type = ["cdylib", "rlib"]; the SDK macro
gates its WASM glue on target_arch = "wasm32" so host integration
tests work out of the box.

Tests: 6 unit + 3 integration, all green. The DOCX integration
test builds a minimal valid DOCX in memory and verifies the
JSON output schema. PDF integration coverage will land in a
follow-up once a representative test fixture is bundled.

The Forgejo CI workflow clones fai/module-sdk into a sibling
location to satisfy the path-based dev dependency. The path
will switch to a versioned git tag once SDK releases stabilize.

Signed-off-by: flemming-it <sf@flemming.it>

Cargo.toml

@@ -0,0 +1,51 @@
+# Standalone Cargo.toml — targets wasm32-wasip2.
+#
+# Build with:
+#   cargo build --release --target wasm32-wasip2
+
+[package]
+name = "text_extract"
+version = "0.1.0"
+edition = "2024"
+authors = ["Dr. Stefan Flemming <platform@flemming.ai>"]
+license = "Apache-2.0"
+publish = false
+description = "F∆I module — extract plain text from PDF and DOCX documents"
+repository = "https://git.flemming.ws/fai-modules/text-extract"
+rust-version = "1.85"
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[dependencies]
+fai-module-sdk = { path = "../../module_sdk/crates/fai-module-sdk" }
+serde = { version = "1", features = ["derive"] }
+pdf-extract = "0.7"
+zip = { version = "2", default-features = false, features = ["deflate"] }
+quick-xml = "0.36"
+
+[dev-dependencies]
+serde_json = "1"
+# Restricted features: deflate64 (a default feature of zip 2.x)
+# requires the unstable `unbounded_shifts` library feature.
+# We only need DEFLATE for round-tripping a minimal DOCX in tests.
+zip = { version = "2", default-features = false, features = ["deflate"] }
+
+[profile.release]
+opt-level = "s"
+lto = true
+codegen-units = 1
+strip = "symbols"
+
+[lints.rust]
+unsafe_op_in_unsafe_fn = "warn"
+
+[lints.clippy]
+unwrap_used = "deny"
+expect_used = "deny"
+panic = "deny"
+print_stdout = "deny"
+print_stderr = "deny"
+
+[workspace]
+# Empty workspace table so this package is NOT picked up by a parent.