[fohara]

Stacked on #39, which is stacked on #40.

What was wrong

lash add "Ship v0.7.0 release notes" -l docs printed
ship-v0-7-0-release-notes while the index stored
ship-v070-release-notes-docs. Anything that copied the printed ID
(lash show, lash complete, @depends-on) failed, and a @depends-on
written against it dangled, which #27's dangling-reference check then rejected.

Two derivations existed and disagreed three ways:

1. v0.7.0 became v0-7-0 in the emitter (punctuation to separator) and v070
   in the parser (punctuation deleted). Same input, two normalizations.
2. The parser slugged the raw checkbox title, so an inline #docs was folded
   into the identity as a -docs suffix. A task's ID should not change because
   someone added a label.
3. Only the parser truncated at 40 characters, so long titles were reported in
   full and stored short.

The fix

lash_types::task::synthesize_task_id is now the one derivation, called by
both the parser and lash add. It strips inline labels before slugging and
truncates, so both sides agree on all three points.

That still leaves the numeric suffix the parser appends to break a collision,
which the emitter cannot know about. So the creation service re-reads the file
it just wrote and reports the ID the parser assigned to the task at that line.
If the re-read fails, the emitter's ID is kept rather than failing a write that
already succeeded.

parse_inline_labels and the new label stripping share one predicate,
label::is_inline_label, so a title loses exactly the words that parsing turns
into labels.

Behaviour change on upgrade

Synthesized IDs for existing tasks change where a title held an inline label or
punctuation inside a word:

• implement-authentication-security becomes implement-authentication
• design-requestresponse-schemas becomes design-request-response-schemas

A @depends-on written against an old synthesized ID needs updating. Explicit
@id: values are untouched. Four CLI snapshots are updated to match; every
changed line is one of those two cases.

Tests

Four integration tests: all three discrepancies in one title, truncation of a
long title, the numeric collision suffix, and the reported ID resolving as a
--depends-on target. All four were confirmed to fail without the fix.