Simplify for release: stand on published crates alone

[zmaril]

Straitjacket could not build anywhere except inside a full powderworks/
checkout, because nine of its dependencies were Cargo path dependencies on
sibling entl and infact trees. That is the one thing standing between it and
being usable. This removes it.

This is subtraction. No surviving rule was changed.

Headline

	before	after
Rust lines (src/ + tests/)	6,995	4,008
Direct dependencies	21	9
Transitive crates in Cargo.lock	377	71
path = "../..." dependencies	9	0
Rules	18	10

Direct dependencies are now anyhow, clap, ignore, inventory, regex,
serde, serde_json, toml, and unic-emoji-char. All from crates.io.

What was removed

Eight rules that read facts from packages that were never published, so none of
them could run outside the repository that built them:

exact-clone, near-clone, library-opportunity, effect-capability,
effect-barrier, unknown-barrier, error-discard, analysis-incomplete.

Those eight were the only RepositoryRule implementations. That made the entire
fact subsystem unreachable, so it goes with them: src/facts.rs, the
AnalysisSelection and FactBatch plumbing, the facts sync and facts status subcommands, and the [facts], [effects], and [errors]
configuration sections.

Rules self-register through inventory, so no core file names a rule. Deleting
all eight compiled clean on the first attempt — the coupling that mattered was
never in the rules, it was that main.rs still reached the fact machinery
through CLI subcommands with no rule left to serve.

What replaced entl-codebase

It was doing language-detection-by-extension and a file walk.

• src/language.rs — the language table: 29 languages with their extensions,
  filenames, shebangs, comment syntax, roles, and the three facets rules gate
  on. A test asserts no two languages claim the same extension.
• src/walk.rs — the file walk, over the ignore crate, which brings
  .gitignore, .ignore, .git/info/exclude, and hidden-file handling. A walk
  error is returned rather than skipped, because a scan over less than the
  requested tree must not be able to report clean.

observe_rust_compiler did not survive the cut. Its only uses were feeding a
core fact-pack request and the test asserting that.

Old configurations

Someone will have one. A configuration naming a removed rule or section now
fails saying the rule was withdrawn, rather than saying the key is unknown,
which reads like a typo:

straitjacket.toml: [facts] configures exact-clone, near-clone and
library-opportunity, which Straitjacket no longer has. Delete the section.

rule(s) Straitjacket no longer has: error-discard. Remove them from the
configuration.

Verification

Built in a scratch directory with no sibling checkouts present, which is the
thing that could not be done before:

cargo build --locked          Finished `dev` profile
cargo test --locked --workspace   48 passed; 0 failed
cargo fmt --all --check       clean
cargo clippy --locked --workspace --all-targets -- -D warnings   clean

grep -rn 'path = "\.\.\|entl\|infact' Cargo.toml Cargo.lock returns nothing.

Text, JSON, and SARIF output all exercised. The SARIF validates against the
OASIS sarif-schema-2.1.0.json, and ruleIndex values still line up after the
rule removals.

Straitjacket runs its full ruleset on itself and is clean.

Also

• CI no longer checks out three repositories side by side. One gate job, no
  weekly schedule — that schedule existed to catch unpinned sibling drift.
• README.md rewritten. It opened with "not ready for use by anyone outside
  this repository" and "Several rules depend on Infact packs that do not exist
  yet". Both are now false.
• Tests and fixtures for removed rules are deleted, not skipped.
• notes/todo.txt deleted; it tracked only removed machinery. The durable parts
  moved into notes/field_guide.md, which is rewritten.

Not done here

The repository stays private and nothing is published. The crate is already
named straitjacket, which is the intended crates.io name. Publishing would
additionally want a repository field in Cargo.toml and a version off
0.1.0.

🤖 Generated with Claude Code

https://claude.ai/code/session_01GbyMWgEUSRGynJwACBvwFu